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Condens. Matter, Volume 7, Issue 1 (March 2022) – 29 articles

Cover Story (view full-size image): We present a new phenomenological picture of Cu and O NMR shift and relaxation data of cuprate superconductors. Planar oxygen data can be understood with a metallic spin density of states which is ubiquitous in all cuprates and for all doping levels, but it carries a temperature independent pseudogap at the Fermi surface, which increases as doping is lowered. The 63Cu shift data show the same metallic density of states and pseudogap features; however, shifts in one direction show a strong dependence on the material family. Whereas O data can be explained within a single spin component scenario, Cu shift anisotropy demands a second spin component which resides on the Cu 3d(x2y2) orbital. View this paper
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17 pages, 1177 KiB  
Article
The Strange-Metal Behavior of Cuprates
by Giovanni Mirarchi, Götz Seibold, Carlo Di Castro, Marco Grilli and Sergio Caprara
Condens. Matter 2022, 7(1), 29; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010029 - 14 Mar 2022
Cited by 4 | Viewed by 2948
Abstract
Recent resonant X-ray scattering experiments on cuprates allowed to identify a new kind of collective excitations, known as charge density fluctuations, which have finite characteristic wave vector, short correlation length and small characteristic energy. It was then shown that these fluctuations provide a [...] Read more.
Recent resonant X-ray scattering experiments on cuprates allowed to identify a new kind of collective excitations, known as charge density fluctuations, which have finite characteristic wave vector, short correlation length and small characteristic energy. It was then shown that these fluctuations provide a microscopic scattering mechanism that accounts for the anomalous transport properties of cuprates in the so-called strange-metal phase and are a source of anomalies in the specific heat. In this work, we retrace the main steps that led us to attributing a central role to charge density fluctuations in the strange-metal phase of cuprates, discuss the state of the art on the issue and provide an in-depth analysis of the contribution of charge density fluctuations to the specific heat. Full article
(This article belongs to the Special Issue Quantum Complex Matter from Charge Density Waves to Superstripes)
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21 pages, 11048 KiB  
Article
Study of Light Polarization by Ferrofluid Film Using Jones Calculus
by Alberto Tufaile, Michael Snyder and Adriana Pedrosa Biscaia Tufaile
Condens. Matter 2022, 7(1), 28; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010028 - 09 Mar 2022
Cited by 4 | Viewed by 3665
Abstract
We studied the polarized light patterns obtained using a thin film of ferrofluid subjected to an applied magnetic field. We obtained patterns of polarized light with magnetic field configurations between parallel plates, monopolar, tetrapolar, and hexapolar, and studied how polarized light varies for [...] Read more.
We studied the polarized light patterns obtained using a thin film of ferrofluid subjected to an applied magnetic field. We obtained patterns of polarized light with magnetic field configurations between parallel plates, monopolar, tetrapolar, and hexapolar, and studied how polarized light varies for different intensities and orientations of the applied magnetic field. Using the Jones calculus, we explored the key optical properties of this system and how these properties relate to the applied magnetic field. We have observed general aspects of polarized light obtained by transmission in a Ferrocell using polariscopes and analyzing the resulting Jones vector, such as the formation and rotation of dark bands known as isogyres. We suggest that in a thin film of ferrofluid as in a Ferrocell, two effects occur. The primary effect is dichroism, which is more sensitive to the component of the magnetic field in the direction parallel to the film plane. The secondary effect is the birefringence that can be observed by analyzing the circular polarization of light. Birefringence is related to the thin film thickness of ferrofluid. Full article
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13 pages, 2996 KiB  
Review
Antimony (Sb)-Based Anodes for Lithium–Ion Batteries: Recent Advances
by Sreejesh Moolayadukkam, Kaveramma Appachettolanda Bopaiah, Priyanka Karathan Parakkandy and Siby Thomas
Condens. Matter 2022, 7(1), 27; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010027 - 05 Mar 2022
Cited by 8 | Viewed by 3829
Abstract
To mitigate the use of fossil fuels and maintain a clean and sustainable environment, electrochemical energy storage systems are receiving great deal of attention, especially rechargeable batteries. This is also associated with the growing demand for electric vehicles, which urged the automotive industries [...] Read more.
To mitigate the use of fossil fuels and maintain a clean and sustainable environment, electrochemical energy storage systems are receiving great deal of attention, especially rechargeable batteries. This is also associated with the growing demand for electric vehicles, which urged the automotive industries to explore the capacities of new materials for use in lithium–ion batteries (LIBs). Graphite is still employed as an anode in large majority of currently available commercial LIBs preserving their better cyclic stability despite enormous research efforts to identify viable alternatives with improved power and energy density. From this point of view, antimony acts as a promising material because it has good theoretical capacity, high volumetric capacity, good reactivity with lithium and good electronic conductivities. Recently, there have been many works that focused on the development of antimony as an alternative anode. This review tries to give a bird’s eye view comprising the experimental and theoretical insights on the developments in the direction of using antimony and antimony composites as anodes for rechargeable Li. Full article
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13 pages, 9562 KiB  
Article
Topological Phases of an Interacting Majorana Benalcazar–Bernevig–Hughes Model
by Alfonso Maiellaro, Fabrizio Illuminati and Roberta Citro
Condens. Matter 2022, 7(1), 26; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010026 - 04 Mar 2022
Cited by 7 | Viewed by 2342
Abstract
We study the effects of Coulomb repulsive interactions on a Majorana Benalcazar–Bernevig–Huges (MBBH) model. The MBBH model belongs to the class of second-order topological superconductors (HOTSC2), featuring robust Majorana corner modes. We consider an interacting strip [...] Read more.
We study the effects of Coulomb repulsive interactions on a Majorana Benalcazar–Bernevig–Huges (MBBH) model. The MBBH model belongs to the class of second-order topological superconductors (HOTSC2), featuring robust Majorana corner modes. We consider an interacting strip of four chains of length L and perform a density matrix renormalization group (DMRG) numerical simulation based on a tensor-network approach. Study of the non-local fermionic correlations and the degenerate entanglement spectrum indicates that the topological phases are robust in the presence of interactions, even in the strongly interacting regime. Full article
(This article belongs to the Special Issue Computational Methods for Quantum Matter)
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8 pages, 1542 KiB  
Article
Electrical Transport Measurements on Layered La(O,F)BiS2 under Extremely High Pressure
by Ryo Matsumoto, Sayaka Yamamoto, Yoshihiro Nemoto, Yuki Nishimiya and Yoshihiko Takano
Condens. Matter 2022, 7(1), 25; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010025 - 02 Mar 2022
Cited by 1 | Viewed by 2270
Abstract
Layered La(O,F)BiS2 exhibits drastic enhancements of the superconducting transition temperature (Tc) under high pressure among the BiS2-based superconducting family. However, the high-pressure application beyond a high-Tc phase of the monoclinic structure has not been conducted. [...] Read more.
Layered La(O,F)BiS2 exhibits drastic enhancements of the superconducting transition temperature (Tc) under high pressure among the BiS2-based superconducting family. However, the high-pressure application beyond a high-Tc phase of the monoclinic structure has not been conducted. In this study, the electrical transport properties in La(O,F)BiS2 single crystal are measured under high pressures up to 83 GPa. An insulating phase without superconductivity is observed under a higher-pressure region above 16 GPa. Moreover, the sample exhibits metallicity and superconductivity above 60 GPa. The newly observed hidden semiconducting phase and reentrant superconductivity have attracted much attention in BiS2-based compounds. Full article
(This article belongs to the Special Issue Layered Superconductors III)
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13 pages, 1510 KiB  
Article
Absence of Spin Frustration in the Kagomé Layers of Cu2+ Ions in Volborthite Cu3V2O7(OH)2·2H2O and Observation of the Suppression and Re-Entrance of Specific Heat Anomalies in Volborthite under an External Magnetic Field
by Myung-Hwan Whangbo, Hyun-Joo Koo, Eva Brücher, Pascal Puphal and Reinhard K. Kremer
Condens. Matter 2022, 7(1), 24; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010024 - 28 Feb 2022
Cited by 1 | Viewed by 1844
Abstract
We determined the spin exchanges between the Cu2+ ions in the kagomé layers of volborthite, Cu3V2O7(OH)2·2H2O, by performing the energy-mapping analysis based on DFT+U calculations, to find that the kagomé layers of [...] Read more.
We determined the spin exchanges between the Cu2+ ions in the kagomé layers of volborthite, Cu3V2O7(OH)2·2H2O, by performing the energy-mapping analysis based on DFT+U calculations, to find that the kagomé layers of Cu2+ ions are hardly spin-frustrated, and the magnetic properties of volborthite below ~75 K should be described by very weakly interacting antiferromagnetic uniform chains made up of effective S = 1/2 pseudospin units. This conclusion was verified by synthesizing single crystals of not only Cu3V2O7(OH)2·2H2O but also its deuterated analogue Cu3V2O7(OD)2·2D2O and then by investigating their magnetic susceptibilities and specific heats. Each kagomé layer consists of intertwined two-leg spin ladders with rungs of linear spin trimers. With the latter acting as S = 1/2 pseudospin units, each two-leg spin ladder behaves as a chain of S = 1/2 pseudospins. Adjacent two-leg spin ladders in each kagomé layer interact very weakly, so it is required that all nearest-neighbor spin exchange paths of every two-leg spin ladder remain antiferromagnetically coupled in all spin ladder arrangements of a kagomé layer. This constraint imposes three sets of entropy spectra with which each kagomé layer can exchange energy with the surrounding on lowering the temperature below ~1.5 K and on raising the external magnetic field B. We discovered that the specific heat anomalies of volborthite observed below ~1.5 K at B = 0 are suppressed by raising the magnetic field B to ~4.2 T, that a new specific heat anomaly occurs when B is increased above ~5.5 T, and that the imposed three sets of entropy spectra are responsible for the field-dependence of the specific heat anomalies. Full article
(This article belongs to the Section Quantum Materials)
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9 pages, 2407 KiB  
Article
Plasma-Generated X-ray Pulses: Betatron Radiation Opportunities at EuPRAXIA@SPARC_LAB
by Francesco Stellato, Maria Pia Anania, Antonella Balerna, Simone Botticelli, Marcello Coreno, Gemma Costa, Mario Galletti, Massimo Ferrario, Augusto Marcelli, Velia Minicozzi, Silvia Morante, Riccardo Pompili, Giancarlo Rossi, Vladimir Shpakov, Fabio Villa and Alessandro Cianchi
Condens. Matter 2022, 7(1), 23; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010023 - 24 Feb 2022
Cited by 4 | Viewed by 2326
Abstract
EuPRAXIA is a leading European project aimed at the development of a dedicated, ground-breaking, ultra-compact accelerator research infrastructure based on novel plasma acceleration concepts and laser technology and on the development of their users’ communities. Within this framework, the Laboratori Nazionali di Frascati [...] Read more.
EuPRAXIA is a leading European project aimed at the development of a dedicated, ground-breaking, ultra-compact accelerator research infrastructure based on novel plasma acceleration concepts and laser technology and on the development of their users’ communities. Within this framework, the Laboratori Nazionali di Frascati (LNF, INFN) will be equipped with a unique combination of an X-band RF LINAC generating high-brightness GeV-range electron beams, a 0.5 PW class laser system and the first fifth-generation free electron laser (FEL) source driven by a plasma-based accelerator, the EuPRAXIA@SPARC_LAB facility. Wiggler-like radiation emitted by electrons accelerated in plasma wakefields gives rise to brilliant, ultra-short X-ray pulses, called betatron radiation. Extensive studies have been performed at the FLAME laser facility at LNF, INFN, where betatron radiation was measured and characterized. The purpose of this paper is to describe the betatron spectrum emitted by particle wakefield acceleration at EuPRAXIA@SPARC_LAB and provide an overview of the foreseen applications of this specific source, thus helping to establish a future user community interested in (possibly coupled) FEL and betatron radiation experiments. In order to provide a quantitative estimate of the expected betatron spectrum and therefore to present suitable applications, we performed simple simulations to determine the spectrum of the betatron radiation emitted at EuPRAXIA@SPARC_LAB. With reference to experiments performed exploiting similar betatron sources, we highlight the opportunities offered by its brilliant femtosecond pulses for ultra-fast X-ray spectroscopy and imaging measurements, but also as an ancillary tool for designing and testing FEL instrumentation and experiments. Full article
(This article belongs to the Special Issue High Precision X-ray Measurements 2021)
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8 pages, 7865 KiB  
Article
Effect of Borophene and Graphene on the Elastic Modulus of PEDOT:PSS Film—A Finite Element Study
by Gbolahan Joseph Adekoya, Oluwasegun Chijioke Adekoya, Emmanuel Rotimi Sadiku, Yskandar Hamam and Suprakas Sinha Ray
Condens. Matter 2022, 7(1), 22; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010022 - 23 Feb 2022
Cited by 7 | Viewed by 2531
Abstract
A finite element method (FEM) was employed to investigate the interaction of borophene nanoplatelets (BNPs) and graphene nanoplatelets (GNPs) on the mechanical properties of Poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) PEDOT:PSS film. A 3D random distribution of the inclusion into the PEDOT:PSS matrix was constructed by [...] Read more.
A finite element method (FEM) was employed to investigate the interaction of borophene nanoplatelets (BNPs) and graphene nanoplatelets (GNPs) on the mechanical properties of Poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) PEDOT:PSS film. A 3D random distribution of the inclusion into the PEDOT:PSS matrix was constructed by developing a 145 × 145 × 145 representative volume element (RVE) with a 4% volume fraction of BNPs and GNPs. In comparison to the pristine PEDOT:PSS, the calculated effective elastic moduli of the BNP-PEDOT:PSS and GNP-PEDOT:PSS nanocomposites exhibited 9.6% and 10.2% improvement, respectively. The predicted FE results were validated by calculating the elastic moduli of the nanocomposites using a modified Halpine-Tsai (H-T) model. The reinforcing effect of the inclusion into the PEDOT:PSS film offers a promising electrode with improved mechanical stability. Consequently, this intriguing result makes the BNP/PEDOT:PSS nanocomposite highly promising for further investigation and application in cutting-edge devices such as touchscreen, thermoelectric, light-emitting diode, electrochemical, photodiode, sensor, solar cell, and electrostatic devices. Full article
(This article belongs to the Special Issue Feature Special Issue for Global Summit on Condensed Matter Physics)
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12 pages, 739 KiB  
Article
Planar Cu and O NMR and the Pseudogap of Cuprate Superconductors
by Marija Avramovska, Jakob Nachtigal, Stefan Tsankov and Jürgen Haase
Condens. Matter 2022, 7(1), 21; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010021 - 23 Feb 2022
Cited by 1 | Viewed by 1887
Abstract
Recently, an analysis of all available planar oxygen shift and relaxation data for the cuprate high-temperature superconductors showed that the data can be understood with a simple spin susceptibility from a metallic density of states common to all cuprates. It carries a doping [...] Read more.
Recently, an analysis of all available planar oxygen shift and relaxation data for the cuprate high-temperature superconductors showed that the data can be understood with a simple spin susceptibility from a metallic density of states common to all cuprates. It carries a doping dependent but temperature independent pseudogap at the Fermi surface, which causes the deviations from normal metallic behavior, also in the specific heat. Here, a more coherent, unbiased assessment of all data, including planar Cu, is presented and consequences are discussed, since the planar Cu data were collected and analyzed prior to the O data. The main finding is that the planar Cu shifts for one direction of the external magnetic field largely follow from the same states and pseudogap. This explains the shift suppression stated more recently, which leads to the failure of the Korringa relation in contrast to an enhancement of the relaxation due to antiferromagnetic spin fluctuations originally proposed. However, there is still the need for a second spin component that appears to be associated with the Cu 3d(x2y2) hole to explain the complex Cu shift anisotropy and family dependence. Furthermore, it is argued that the planar Cu relaxation which was reported recently to be rather ubiquitous for the cuprates, must be related to this universal density of states and the second spin component, while not being affected by the simple pseudogap. Thus, while this universal metallic density of states with a pseudogap is also found in the planar Cu data, there is still need for a more elaborate scenario that eludes planar O. Full article
(This article belongs to the Section Superconductivity)
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13 pages, 8539 KiB  
Article
Microstructural Analysis of Terbium Doped Zirconia and Its Biological Studies
by Suganthan Veerachamy and Sivakumar Rajagopal
Condens. Matter 2022, 7(1), 20; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010020 - 03 Feb 2022
Viewed by 2005
Abstract
Zirconia has its place in the biomedical industry because of its mechanical strength, bio-inertness, and physiochemical properties. Zirconia was synthesized and doped with Terbium (Tb), a lanthanide that was reported to show a photoluminescence property, which was a major characteristic for carcinogenic studies. [...] Read more.
Zirconia has its place in the biomedical industry because of its mechanical strength, bio-inertness, and physiochemical properties. Zirconia was synthesized and doped with Terbium (Tb), a lanthanide that was reported to show a photoluminescence property, which was a major characteristic for carcinogenic studies. Zirconia and Tb doped Zirconia were synthesized using the co-precipitation technique and were sintered at a temperature ranging from 900 to 1200 °C. The Zirconia sample and Tb doped Zirconia were thus studied for structural diversities using the X-ray powder diffraction technique (XRD), FTIR, FE-SEM, and TEM. From XRD, Zirconia phase transformation from monoclinic to tetragonal phase was observed, which signified limited fracture, elasticity, and crack formation. It was evident that Terbium stabilized the tetragonal phase of Zirconia, which reportedly shows mechanical properties, which include fracture toughness and flexural strength. The particle size of the Zirconia was comparatively more than the Tb doped Zirconia. The particle size of Zirconia ranged between 176 nm and 393 nm and the particle size of Tb doped Zirconia ranged between 110 nm and 343 nm. The biocompatibility of both the samples was tested using an Mg-63 cell line, and the cell viability was observed to be higher in Tb doped Zirconia when compared to the undoped Zirconia sample. Full article
(This article belongs to the Special Issue Electronic Materials and Devices 2021)
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16 pages, 412 KiB  
Article
The 1S0 Pairing Gap in Neutron Matter
by Stefano Gandolfi, Georgios Palkanoglou, Joseph Carlson, Alexandros Gezerlis and Kevin E. Schmidt
Condens. Matter 2022, 7(1), 19; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010019 - 01 Feb 2022
Cited by 8 | Viewed by 2322
Abstract
We report ab initio calculations of the S wave pairing gap in neutron matter calculated using realistic nuclear Hamiltonians that include two- and three-body interactions. We use a trial state, properly optimized to capture the essential pairing correlations, from which we extract ground [...] Read more.
We report ab initio calculations of the S wave pairing gap in neutron matter calculated using realistic nuclear Hamiltonians that include two- and three-body interactions. We use a trial state, properly optimized to capture the essential pairing correlations, from which we extract ground state properties by means of auxiliary field diffusion Monte Carlo simulations. We extrapolate our results to the thermodynamic limit by studying the finite-size effects in the symmetry-restored projected Bardeen-Cooper-Schrieffer (PBCS) theory and compare our results to other ab initio studies done in the past. Our quantum Monte Carlo results for the pairing gap show a modest suppression with respect to the mean-field BCS values. These results can be connected to cold atom experiments, via the unitarity regime where fermionic superfluidity assumes a unified description, and they are important in the prediction of thermal properties and the cooling of neutron stars. Full article
(This article belongs to the Special Issue Computational Methods for Quantum Matter)
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13 pages, 1550 KiB  
Article
Mimicking Multiorbital Systems with SU(N) Atoms: Hund’s Physics and Beyond
by Andrea Richaud, Matteo Ferraretto and Massimo Capone
Condens. Matter 2022, 7(1), 18; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010018 - 01 Feb 2022
Cited by 2 | Viewed by 2511
Abstract
The physics of many interesting correlated materials can be captured by multiorbital Hubbard models, where conduction electrons feature an additional orbital degree of freedom. The multiorbital characteristic is not a mere complication, but it leads to an immensely richer landscape of physical regimes. [...] Read more.
The physics of many interesting correlated materials can be captured by multiorbital Hubbard models, where conduction electrons feature an additional orbital degree of freedom. The multiorbital characteristic is not a mere complication, but it leads to an immensely richer landscape of physical regimes. One of the key features is the interplay between Hubbard repulsion and Hund’s exchange coupling, which has been shown to lead to orbital-selective correlations and to the existence of correlation-resilient metals (usually called Hund’s metals) defying Mott localization. Here, we show that experimentally available platforms of SU(N)-symmetric ultracold atoms can indeed mimic the rich physics disclosed by multiorbital materials, by exploiting the internal degrees of freedom of multicomponent atoms. We discuss in detail the SU(N) version of interaction-resilient Hund’s metal and some other interesting regimes. Full article
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9 pages, 931 KiB  
Article
Quantum Reservoir Computing for Speckle Disorder Potentials
by Pere Mujal
Condens. Matter 2022, 7(1), 17; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010017 - 28 Jan 2022
Cited by 5 | Viewed by 2601
Abstract
Quantum reservoir computing is a machine learning approach designed to exploit the dynamics of quantum systems with memory to process information. As an advantage, it presents the possibility to benefit from the quantum resources provided by the reservoir combined with a simple and [...] Read more.
Quantum reservoir computing is a machine learning approach designed to exploit the dynamics of quantum systems with memory to process information. As an advantage, it presents the possibility to benefit from the quantum resources provided by the reservoir combined with a simple and fast training strategy. In this work, this technique is introduced with a quantum reservoir of spins and it is applied to find the ground state energy of an additional quantum system. The quantum reservoir computer is trained with a linear model to predict the lowest energy of a particle in the presence of different speckle disorder potentials. The performance of the task is analyzed with a focus on the observable quantities extracted from the reservoir and it is shown to be enhanced when two-qubit correlations are employed. Full article
(This article belongs to the Special Issue Computational Methods for Quantum Matter)
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11 pages, 1711 KiB  
Article
Benchmarking Plane Waves Quantum Mechanical Calculations of Iron(II) Tris(2,2′-bipyridine) Complex by X-ray Absorption Spectroscopy
by Nico Sanna and Maurizio Benfatto
Condens. Matter 2022, 7(1), 16; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010016 - 27 Jan 2022
Cited by 1 | Viewed by 2775
Abstract
In this work, we used, for the first time, a computational Self-Consistent Field procedure based on plane waves to describe the low and high spin conformational states of the complex [Fe(bpy)3]2+. The results obtained in the study of the minimum [...] Read more.
In this work, we used, for the first time, a computational Self-Consistent Field procedure based on plane waves to describe the low and high spin conformational states of the complex [Fe(bpy)3]2+. The results obtained in the study of the minimum energy structures of this complex, a prototype of a wide class of compounds called Spin Cross Over, show how the plane wave calculations are in line with the most recent studies based on gaussian basis set functions and, above all, reproduce within acceptable errors the experimental spectra of X-ray absorption near-edge structure spectroscopy (XANES). This preliminary study shows the capabilities of plane wave methods to correctly describe the molecular structures of metal-organic complexes of this type and paves the way for future even complex computational simulations based on the energy gradient, such as Nudge Elastic Band or ab-initio Born-Oppenheimer molecular dynamics. Full article
(This article belongs to the Special Issue High Precision X-ray Measurements 2021)
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21 pages, 4233 KiB  
Article
Polaron-Depleton Transition in the Yrast Excitations of a One-Dimensional Bose Gas with a Mobile Impurity
by Mingrui Yang, Matija Čufar, Elke Pahl and Joachim Brand
Condens. Matter 2022, 7(1), 15; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010015 - 26 Jan 2022
Cited by 5 | Viewed by 2545
Abstract
We present exact numerical data for the lowest-energy momentum eigenstates (yrast states) of a repulsive spin impurity in a one-dimensional Bose gas using full configuration interaction quantum Monte Carlo (FCIQMC). As a stochastic extension of exact diagonalization, it is well suited for the [...] Read more.
We present exact numerical data for the lowest-energy momentum eigenstates (yrast states) of a repulsive spin impurity in a one-dimensional Bose gas using full configuration interaction quantum Monte Carlo (FCIQMC). As a stochastic extension of exact diagonalization, it is well suited for the study of yrast states of a lattice-renormalized model for a quantum gas. Yrast states carry valuable information about the dynamic properties of slow-moving mobile impurities immersed in a many-body system. Based on the energies and the first and second-order correlation functions of yrast states, we identify different dynamical regimes and the transitions between them: The polaron regime, where the impurity’s motion is affected by the Bose gas through a renormalized effective mass; a regime of a gray soliton that is weakly correlated with a stationary impurity, and the depleton regime, where the impurity occupies a dark or gray soliton. Extracting the depleton effective mass reveals a super heavy regime where the magnitude of the (negative) depleton mass exceeds the mass of the finite Bose gas. Full article
(This article belongs to the Special Issue Computational Methods for Quantum Matter)
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2 pages, 195 KiB  
Editorial
Acknowledgment to Reviewers of Condensed Matter in 2021
by Condensed Matter Editorial Office
Condens. Matter 2022, 7(1), 14; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010014 - 25 Jan 2022
Viewed by 1438
Abstract
Rigorous peer-reviews are the basis of high-quality academic publishing [...] Full article
24 pages, 554 KiB  
Article
Toward an Automated-Algebra Framework for High Orders in the Virial Expansion of Quantum Matter
by Aleks J. Czejdo, Joaquin E. Drut, Yaqi Hou and Kaitlyn J. Morrell
Condens. Matter 2022, 7(1), 13; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010013 - 24 Jan 2022
Cited by 3 | Viewed by 2483
Abstract
The virial expansion provides a non-perturbative view into the thermodynamics of quantum many-body systems in dilute regimes. While powerful, the expansion is challenging as calculating its coefficients at each order n requires analyzing (if not solving) the quantum n-body problem. In this [...] Read more.
The virial expansion provides a non-perturbative view into the thermodynamics of quantum many-body systems in dilute regimes. While powerful, the expansion is challenging as calculating its coefficients at each order n requires analyzing (if not solving) the quantum n-body problem. In this work, we present a comprehensive review of automated algebra methods, which we developed to calculate high-order virial coefficients. The methods are computational but non-stochastic, thus avoiding statistical effects; they are also for the most part analytic, not numerical, and amenable to massively parallel computer architectures. We show formalism and results for coefficients characterizing the thermodynamics (pressure, density, energy, static susceptibilities) of homogeneous and harmonically trapped systems and explain how to generalize them to other observables such as the momentum distribution, Tan contact, and the structure factor. Full article
(This article belongs to the Special Issue Computational Methods for Quantum Matter)
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20 pages, 1154 KiB  
Review
Comparison of Ferromagnetic Materials: Past Work, Recent Trends, and Applications
by Prithivi Rasaili, Nitin Kumar Sharma and Ajaya Bhattarai
Condens. Matter 2022, 7(1), 12; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010012 - 24 Jan 2022
Cited by 9 | Viewed by 5078
Abstract
Despite our traditional concept-based understanding of ferromagnetism, an investigation of this phenomenon has revealed several other facts. Ferromagnetism was previously supposed to be exhibited by only a few elements. Subsequently, it was realized that specific elements with d- or f- orbitals demonstrated this [...] Read more.
Despite our traditional concept-based understanding of ferromagnetism, an investigation of this phenomenon has revealed several other facts. Ferromagnetism was previously supposed to be exhibited by only a few elements. Subsequently, it was realized that specific elements with d- or f- orbitals demonstrated this phenomenon. When elements without these orbitals exhibited ferromagnetism, intrinsic origin-based and structural defect-based theories were introduced. At present, nonmagnetic oxides, hexaborides of alkaline-earth metals, carbon structures, and nonmetallic non-oxide compounds are gaining significant attention owing to their potential applications in spintronics, electronics, biomedicine, etc. Therefore, herein, previous work, recent trends, and the applications of these materials and studies based on relevant topics, ranging from the traditional understanding of ferromagnetism to the most recent two-element-based systems, are reviewed. Full article
(This article belongs to the Special Issue Electronic Materials and Devices 2021)
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13 pages, 3344 KiB  
Article
ARIA—A VUV Beamline for EuPRAXIA@SPARC_LAB
by Fabio Villa, Marcello Coreno, Zeinab Ebrahimpour, Luca Giannessi, Augusto Marcelli, Michele Opromolla, Vittoria Petrillo and Francesco Stellato
Condens. Matter 2022, 7(1), 11; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010011 - 22 Jan 2022
Cited by 5 | Viewed by 2182
Abstract
EuPRAXIA@SPARC_LAB is a new Free Electron Laser (FEL) facility that is currently under construction at the Laboratori Nazionali di Frascati of the INFN. The electron beam driving the FEL will be delivered by an X-band normal conducting LINAC followed by a plasma wakefield [...] Read more.
EuPRAXIA@SPARC_LAB is a new Free Electron Laser (FEL) facility that is currently under construction at the Laboratori Nazionali di Frascati of the INFN. The electron beam driving the FEL will be delivered by an X-band normal conducting LINAC followed by a plasma wakefield acceleration stage. It will be characterized by a small footprint and will deliver ultra-bright photon pulses for experiments in the water window to the user community. In addition to the soft-X-rays beamline already planned in the project, we propose the installation of a second photon beamline with seeded FEL pulses in the range between 50 and 180 nm. Here, we will present the FEL generation scheme, the layout of the dedicated beamline and the potential applications of the FEL radiation source in this low energy range. Full article
(This article belongs to the Special Issue High Precision X-ray Measurements 2021)
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25 pages, 694 KiB  
Article
Weakly-Interacting Bose–Bose Mixtures from the Functional Renormalisation Group
by Felipe Isaule and Ivan Morera
Condens. Matter 2022, 7(1), 9; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010009 - 20 Jan 2022
Cited by 3 | Viewed by 2395
Abstract
We provide a detailed presentation of the functional renormalisation group (FRG) approach for weakly-interacting Bose–Bose mixtures, including a complete discussion on the RG equations. To test this approach, we examine thermodynamic properties of balanced three-dimensional Bose–Bose gases at zero and finite temperatures and [...] Read more.
We provide a detailed presentation of the functional renormalisation group (FRG) approach for weakly-interacting Bose–Bose mixtures, including a complete discussion on the RG equations. To test this approach, we examine thermodynamic properties of balanced three-dimensional Bose–Bose gases at zero and finite temperatures and find a good agreement with related works. We also study ground-state energies of repulsive Bose polarons by examining mixtures in the limit of infinite population imbalance. Finally, we discuss future applications of the FRG to novel problems in Bose–Bose mixtures and related systems. Full article
(This article belongs to the Special Issue Computational Methods for Quantum Matter)
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17 pages, 1111 KiB  
Article
Superconductivity and the Jahn–Teller Polaron
by Annette Bussmann-Holder and Hugo Keller
Condens. Matter 2022, 7(1), 10; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010010 - 20 Jan 2022
Viewed by 2565
Abstract
In this article, we review the essential properties of high-temperature superconducting cuprates, which are unconventional isotope effects, heterogeneity, and lattice responses. Since their discovery was based on ideas stemming from Jahn–Teller polarons, their special role, together with the Jahn–Teller effect itself, is discussed [...] Read more.
In this article, we review the essential properties of high-temperature superconducting cuprates, which are unconventional isotope effects, heterogeneity, and lattice responses. Since their discovery was based on ideas stemming from Jahn–Teller polarons, their special role, together with the Jahn–Teller effect itself, is discussed in greater detail. We conclude that the underlying physics of cuprates cannot stem from purely electronic mechanisms, but that the intricate interaction between lattice and charge is at its origin. Full article
(This article belongs to the Special Issue Recent Advances in High-Temperature Superconductivity)
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9 pages, 513 KiB  
Article
Anodic Activity of Hydrated and Anhydrous Iron (II) Oxalate in Li-Ion Batteries
by Fatemeh Keshavarz, Marius Kadek, Bernardo Barbiellini and Arun Bansil
Condens. Matter 2022, 7(1), 8; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010008 - 12 Jan 2022
Cited by 3 | Viewed by 2781
Abstract
We discuss the applicability of the naturally occurring compound Ferrous Oxalate Dihydrate (FOD) (FeC2O4·2H2O) as an anode material in Li-ion batteries. Using first-principles modeling, we evaluate the electrochemical activity of FOD and demonstrate how its structural water [...] Read more.
We discuss the applicability of the naturally occurring compound Ferrous Oxalate Dihydrate (FOD) (FeC2O4·2H2O) as an anode material in Li-ion batteries. Using first-principles modeling, we evaluate the electrochemical activity of FOD and demonstrate how its structural water content affects the intercalation reaction and contributes to its performance. We show that both Li0 and Li+ intercalation in FOD yields similar results. Our analysis indicates that fully dehydrated ferrous oxalate is a more promising anodic material with higher electrochemical stability: it carries 20% higher theoretical Li storage capacity and a lower voltage (0.68 V at the PBE/cc-pVDZ level), compared to its hydrated (2.29 V) or partially hydrated (1.43 V) counterparts. Full article
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10 pages, 28120 KiB  
Article
Tin Whisker Growth Suppression Using NiO Sublayers Fabricated by Dip Coating
by Jacob D. Buchanan, Vamsi Borra, Md Maidul Islam, Daniel G. Georgiev and Srikanth Itapu
Condens. Matter 2022, 7(1), 7; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010007 - 06 Jan 2022
Viewed by 2161
Abstract
Whiskers are small crystalline growths, which can grow from certain metals or alloys. Reaching up to several millimeters long, whiskers have the potential to cause device failures due to short circuits and contamination by debris. Tin (Sn) is one such metal that is [...] Read more.
Whiskers are small crystalline growths, which can grow from certain metals or alloys. Reaching up to several millimeters long, whiskers have the potential to cause device failures due to short circuits and contamination by debris. Tin (Sn) is one such metal that is particularly prone to whisker development. Until the 2006 RoHS Initiative, lead (Pb) was added to tin in small amounts (up to 2%) to greatly reduce the growth of whiskers. Since then, however, industry has switched to lead-free tin solders and coatings, and the issue of whisker growth on tin has attracted new interest. A reactive-sputtering-deposited nickel oxide sublayer was shown recently to strongly suppress the growth of whiskers from an overlaying tin layer. This paper reports on using nickel oxide films, obtained by a sol–gel dip coating method, as whisker suppressing sublayers. The proposed method is simple, low-cost, and can easily be scaled up for manufacturing purposes. The properties of the sol–gel deposited nickel oxide film were examined using SEM, EDS, and Raman spectroscopy. Samples containing the nickel oxide sublayer were observed through SEM periodically over several months to examine the surfaces for whisker development, and the results show that such layers can be very effective in suppressing whisker growth. Full article
(This article belongs to the Special Issue Electronic Materials and Devices 2021)
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33 pages, 1584 KiB  
Review
Electrode Materials for Supercapacitors in Hybrid Electric Vehicles: Challenges and Current Progress
by Sivakumar Rajagopal, Rameez Pulapparambil Vallikkattil, M. Mohamed Ibrahim and Dimiter Georgiev Velev
Condens. Matter 2022, 7(1), 6; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010006 - 06 Jan 2022
Cited by 62 | Viewed by 7261
Abstract
For hybrid electric vehicles, supercapacitors are an attractive technology which, when used in conjunction with the batteries as a hybrid system, could solve the shortcomings of the battery. Supercapacitors would allow hybrid electric vehicles to achieve high efficiency and better power control. Supercapacitors [...] Read more.
For hybrid electric vehicles, supercapacitors are an attractive technology which, when used in conjunction with the batteries as a hybrid system, could solve the shortcomings of the battery. Supercapacitors would allow hybrid electric vehicles to achieve high efficiency and better power control. Supercapacitors possess very good power density. Besides this, their charge-discharge cycling stability and comparatively reasonable cost make them an incredible energy-storing device. The manufacturing strategy and the major parts like electrodes, current collector, binder, separator, and electrolyte define the performance of a supercapacitor. Among these, electrode materials play an important role when it comes to the performance of supercapacitors. They resolve the charge storage in the device and thus decide the capacitance. Porous carbon, conductive polymers, metal hydroxide, and metal oxides, which are some of the usual materials used for the electrodes in the supercapacitors, have some limits when it comes to energy density and stability. Major research in supercapacitors has focused on the design of stable, highly efficient electrodes with low cost. In this review, the most recent electrode materials used in supercapacitors are discussed. The challenges, current progress, and future development of supercapacitors are discussed as well. This study clearly shows that the performance of supercapacitors has increased considerably over the years and this has made them a promising alternative in the energy sector. Full article
(This article belongs to the Special Issue Electronic Materials and Devices 2021)
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28 pages, 26059 KiB  
Article
Innovative Analytical Method for X-ray Imaging and Space-Resolved Spectroscopy of ECR Plasmas
by Eugenia Naselli, Richard Rácz, Sandor Biri, Maria Mazzaglia, Luigi Celona, Santo Gammino, Giuseppe Torrisi, Zoltan Perduk, Alessio Galatà and David Mascali
Condens. Matter 2022, 7(1), 5; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010005 - 28 Dec 2021
Cited by 11 | Viewed by 2409
Abstract
At the Italian National Institute for Nuclear Physics-Southern National Laboratory (INFN-LNS), and in collaboration with the ATOMKI laboratories, an innovative multi-diagnostic system with advanced analytical methods has been designed and implemented. This is based on several detectors and techniques (Optical Emission Spectroscopy, RF [...] Read more.
At the Italian National Institute for Nuclear Physics-Southern National Laboratory (INFN-LNS), and in collaboration with the ATOMKI laboratories, an innovative multi-diagnostic system with advanced analytical methods has been designed and implemented. This is based on several detectors and techniques (Optical Emission Spectroscopy, RF systems, interfero-polarimetry, X-ray detectors), and here we focus on high-resolution, spatially resolved X-ray spectroscopy, performed by means of a X-ray pin-hole camera setup operating in the 0.5–20 keV energy domain. The diagnostic system was installed at a 14 GHz Electron Cyclotron Resonance (ECR) ion source (ATOMKI, Debrecen), enabling high-precision, X-ray, spectrally resolved imaging of ECR plasmas heated by hundreds of Watts. The achieved spatial and energy resolutions were 0.5 mm and 300 eV at 8 keV, respectively. Here, we present the innovative analysis algorithm that we properly developed to obtain Single Photon-Counted (SPhC) images providing the local plasma-emitted spectrum in a High-Dynamic-Range (HDR) mode, by distinguishing fluorescence lines of the materials of the plasma chamber (Ti, Ta) from plasma (Ar). This method allows for a quantitative characterization of warm electrons population in the plasma (and its 2D distribution), which are the most important for ionization, and to estimate local plasma density and spectral temperatures. The developed post-processing analysis is also able to remove the readout noise that is often observable at very low exposure times (msec). The setup is now being updated, including fast shutters and trigger systems to allow simultaneous space and time-resolved plasma spectroscopy during transients, stable and turbulent regimes. Full article
(This article belongs to the Special Issue High Precision X-ray Measurements 2021)
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7 pages, 614 KiB  
Article
Magnetic Compton Scattering Study of Li-Rich Battery Materials
by Kosuke Suzuki, Yuji Otsuka, Kazushi Hoshi, Hiroshi Sakurai, Naruki Tsuji, Kentaro Yamamoto, Naoaki Yabuuchi, Hasnain Hafiz, Yuki Orikasa, Yoshiharu Uchimoto, Yoshiharu Sakurai, Venkatasubramanian Viswanathan, Arun Bansil and Bernardo Barbiellini
Condens. Matter 2022, 7(1), 4; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010004 - 28 Dec 2021
Cited by 6 | Viewed by 3093
Abstract
The redox process in a lithium-ion battery occurs when a conduction electron from the lithium anode is transferred to the redox orbital of the cathode. Understanding the nature of orbitals involved in anionic as well as cationic redox reactions is important for improving [...] Read more.
The redox process in a lithium-ion battery occurs when a conduction electron from the lithium anode is transferred to the redox orbital of the cathode. Understanding the nature of orbitals involved in anionic as well as cationic redox reactions is important for improving the capacity and energy density of Li-ion batteries. In this connection, we have obtained magnetic Compton profiles (MCPs) from the Li-rich cation-disordered rock-salt compound LixTi0.4Mn0.4O2 (LTMO). The MCPs, which involved the scattering of circularly polarized hard X-rays, are given by the momentum density of all the unpaired spins in the material. The net magnetic moment in the ground state can be extracted from the area under the MCP, along with a SQUID measurement. Our analysis gives insight into the role of Mn 3d magnetic electrons and O 2p holes in the magnetic redox properties of LTMO. Full article
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9 pages, 875 KiB  
Article
High-Sensitivity X-ray Phase Imaging System Based on a Hartmann Wavefront Sensor
by Ginevra Begani Provinciali, Martin Piponnier, Laura Oudjedi, Xavier Levecq, Fabrice Harms, Alessia Cedola, Ombeline de La Rochefoucauld and Philippe Zeitoun
Condens. Matter 2022, 7(1), 3; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010003 - 27 Dec 2021
Cited by 2 | Viewed by 2165
Abstract
The Hartman wavefront sensor can be used for X-ray phase imaging with high angular resolution. The Hartmann sensor is able to retrieve both the phase and absorption from a single acquisition. The system calculates the shift in a series of apertures imaged with [...] Read more.
The Hartman wavefront sensor can be used for X-ray phase imaging with high angular resolution. The Hartmann sensor is able to retrieve both the phase and absorption from a single acquisition. The system calculates the shift in a series of apertures imaged with a detector with respect to their reference positions. In this article, the impact of the reference image on the final image quality is investigated using a laboratory setup. Deflection and absorption images of the same sample are compared using reference images acquired in air and in water. It can be easily coupled with tomographic setups to obtain 3D images of both phase and absorption. Tomographic images of a test sample are shown, where deflection images revealed details that were invisible in absorption. The findings reported in this paper can be used for the improvement of image reconstruction and for expanding the applications of X-ray phase imaging towards materials characterization and medical imaging. Full article
(This article belongs to the Special Issue High Precision X-ray Measurements 2021)
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8 pages, 2802 KiB  
Article
High-Precision X-ray Total Scattering Measurements Using a High-Accuracy Detector System
by Kenichi Kato and Kazuya Shigeta
Condens. Matter 2022, 7(1), 2; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010002 - 24 Dec 2021
Cited by 1 | Viewed by 2105
Abstract
The total scattering method, which is based on measurements of both Bragg and diffuse scattering on an equal basis, has been still challenging even by means of synchrotron X-rays. This is because such measurements require a wide coverage in scattering vector Q, [...] Read more.
The total scattering method, which is based on measurements of both Bragg and diffuse scattering on an equal basis, has been still challenging even by means of synchrotron X-rays. This is because such measurements require a wide coverage in scattering vector Q, high Q resolution, and a wide dynamic range for X-ray detectors. There is a trade-off relationship between the coverage and resolution in Q, whereas the dynamic range is defined by differences in X-ray response between detector channels (X-ray response non-uniformity: XRNU). XRNU is one of the systematic errors for individual channels, while it appears to be a random error for different channels. In the present study, taking advantage of the randomness, the true sensitivity for each channel has been statistically estimated. Results indicate that the dynamic range of microstrip modules (MYTHEN, Dectris, Baden-Daettwil, Switzerland), which have been assembled for a total scattering measurement system (OHGI), has been successfully restored from 104 to 106. Furthermore, the correction algorithm has been optimized to increase time efficiencies. As a result, the correcting time has been reduced from half a day to half an hour, which enables on-demand correction for XRNU according to experimental settings. High-precision X-ray total scattering measurements, which has been achieved by a high-accuracy detector system, have demonstrated valence density studies from powder and PDF studies for atomic displacement parameters. Full article
(This article belongs to the Special Issue High Precision X-ray Measurements 2021)
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11 pages, 860 KiB  
Article
Reflection Efficiency and Spectra Resolutions Ray-Tracing Simulations for the VOXES HAPG Crystal Based Von Hamos Spectrometer
by Veronica De Leo, Alessandro Scordo, Catalina Curceanu, Marco Miliucci and Florin Sirghi
Condens. Matter 2022, 7(1), 1; https://0-doi-org.brum.beds.ac.uk/10.3390/condmat7010001 - 24 Dec 2021
Cited by 2 | Viewed by 2130
Abstract
The VOXES collaboration at INFN National Laboratories of Frascati developed a prototype of a high resolution Von Hamos X-ray spectrometer using HAPG (Highly Annealed Pyrolytic Graphite) mosaic crystals. This technology allows the employment of extended isotropic sources and could find application in several [...] Read more.
The VOXES collaboration at INFN National Laboratories of Frascati developed a prototype of a high resolution Von Hamos X-ray spectrometer using HAPG (Highly Annealed Pyrolytic Graphite) mosaic crystals. This technology allows the employment of extended isotropic sources and could find application in several physics fields. The capability of the spectrometer to reach energy precision and resolution below 1 and 10 eV, respectively, when used with wide sources, has been already demonstrated. Recently, the response of this device, for a ρ = 206.7 mm cylindrically bent HAPG crystal using CuKα1,2 and FeKα1,2 XRF lines, has been investigated in terms of reflection efficiency by a dedicated ray-tracing simulation. Details of the simulation procedure and the comparison with the experimental results are presented. This study is crucial in order to retrieve information on the spectrometer signal collection efficiency, especially in the energy range in which the standard calibration procedures cannot be applied. Full article
(This article belongs to the Special Issue High Precision X-ray Measurements 2021)
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