Submit to Molecules Review for Molecules Propose a Special Issue

Journal Browser

► Journal Browser

Molecular Magnetism: Modern Trends and Future Perspectives

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Materials Chemistry".

Deadline for manuscript submissions: closed (30 April 2023) | Viewed by 11401

Share This Special Issue

Special Issue Editor

Dr. Jozef Strečka

E-Mail Website
Guest Editor

Department of Theoretical Physics and Astrophysics, Faculty of Science, Pavol Jozef Šafárik University in Košice, Park Angelinum 9, 040 01 Košice, Slovakia
Interests: exactly solved models in statistical mechanics; classical and quantum theory of magnetism; phase transitions and critical phenomena; statistical mechanics of liquids

Special Issue Information

Dear Colleagues,

Molecular nanomagnets are among the most promising electron spin systems for quantum computation and quantum information processing. The bistable nature of single-molecule and single-chain magnets with a slow magnetic relaxation may be implemented, for instance, for efficient information storage. The present Special Issue is devoted to the comprehensive theoretical and experimental study of the magnetization process and the dynamical and thermodynamical properties of selected molecular magnetic materials, which may be of crucial importance for the development of future quantum technologies. Among other matters, the quantum entanglement as a key resource for quantum computation, quantum communication, and quantum information processing will be investigated within a certain class of molecular magnetic materials both theoretically and experimentally.

The aim of this Special Issue of the journal Molecules entitled “Molecular Magnetism: Modern Trends and Future Perspectives” is to collect papers deepening a current knowledge on molecular magnetic materials, whereas the scope of the special issue is focused but not limited to modern trends and future perspectives of molecular magnetic materials in development of novel quantum technologies. The papers based on either theoretical or experimental results are welcome, whereas the studies combining both theoretical as well as experimental approaches would be especially valuable.

It is my great pleasure to invite you to submit your manuscripts presenting recent original results to this Special Issue of the journal Molecules.

Dr. Jozef Strečka
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

Single-molecule and single-chain magnets
Quantum tunneling of magnetization
Exotic quantum states
Magnetization plateaus
Quantum computation and information
Quantum entanglement

Published Papers (6 papers)

Download All Papers

Research

23 pages, 3415 KiB

Open AccessArticle

Phase Diagram and Quantum Entanglement Properties of a Pentamer S = 1/2 Heisenberg Spin Cluster

by Karol Szałowski

Molecules 2023, 28(17), 6418; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules28176418 - 03 Sep 2023

Viewed by 945

Abstract

Cluster molecular magnets prove their potential for applications in quantum technologies, encouraging studies of quantum entanglement in spin systems. In the paper we discuss quantum entanglement properties of pentamer cluster composed of spins

S = 1 / 2

forming a tetrahedron with additional [...] Read more.

S = 1 / 2

forming a tetrahedron with additional spin in its center, with geometry reproducing the smallest nonplanar graph. We model the system with isotropic Heisenberg Hamiltonian including external magnetic field and use exact diagonalization approach to explore the ground-state phase diagram and thermodynamic properties within canonical ensemble formalism. We focus the interest on two-spin entanglement quantified by Wootters concurrence. For ground state, we find two states with total cluster spin equal to 3/2 exhibiting entanglement, occurring preferably for antiferromagnetic interactions. For finite temperatures, we predict the presence of magnetic-field-induced entanglement as well as temperature-induced entanglement. Full article

(This article belongs to the Special Issue Molecular Magnetism: Modern Trends and Future Perspectives)

► Show Figures

Figure 1

15 pages, 7862 KiB

Open AccessArticle

Distribution of Bipartite and Tripartite Entanglement within a Spin-1/2 Heisenberg Star in a Magnetic Field

by Katarína Karlόvá and Jozef Strečka

Molecules 2023, 28(10), 4037; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules28104037 - 11 May 2023

Cited by 1 | Viewed by 917

Abstract

The spatial distribution of entanglement within a spin-1/2 Heisenberg star composed from a single central spin and three peripheral spins is examined in the presence of an external magnetic field using the Kambe projection method, which allows an exact calculation of the bipartite and tripartite negativity serving as a measure of the bipartite and tripartite entanglement. Apart from a fully separable polarized ground state emergent at high-enough magnetic fields, the spin-1/2 Heisenberg star exhibits at lower magnetic fields three outstanding nonseparable ground states. The first quantum ground state exhibits the bipartite and tripartite entanglement over all possible decompositions of the spin star into any pair or triad of spins, whereby the bipartite and tripartite entanglement between the central and peripheral spins dominates over that between the peripheral spins. The second quantum ground state has a remarkably strong tripartite entanglement between any triad of spins in spite of the lack of bipartite entanglement. The central spin of the spin star is separable from the remaining three peripheral spins within the third quantum ground state, where the peripheral spins are subject to the strongest tripartite entanglement arising from a two-fold degenerate W-state. Full article

(This article belongs to the Special Issue Molecular Magnetism: Modern Trends and Future Perspectives)

► Show Figures

Figure 1

23 pages, 3482 KiB

Open AccessArticle

Numerical Interchain Mean-Field Theory for the Specific Heat of the Bimetallic Ferromagnetically Coupled Chain Compound MnNi(NO₂)₄(en)₂ (en = Ethylenediamine)

by Andreas Honecker, Wolfram Brenig, Maheshwor Tiwari, Ralf Feyerherm, Matthias Bleckmann and Stefan Süllow

Molecules 2022, 27(19), 6546; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27196546 - 03 Oct 2022

Cited by 1 | Viewed by 1685

Abstract

We present a detailed study of the field-dependent specific heat of the bimetallic ferromagnetically coupled chain compound MnNi(NO

_{2}

)

_{4}

(en)

_{2}

, en = ethylenediamine. For this material, which in zero field orders antiferromagnetically below

T_{N} = 2.45

K, small [...] Read more.

We present a detailed study of the field-dependent specific heat of the bimetallic ferromagnetically coupled chain compound MnNi(NO

_{2}

)

_{4}

(en)

_{2}

, en = ethylenediamine. For this material, which in zero field orders antiferromagnetically below

T_{N} = 2.45

K, small fields suppress magnetic order. Instead, in such fields, a double-peak-like structure in the temperature dependence of the specific heat is observed. We attribute this behavior to the existence of an acoustic and an optical mode in the spin-wave dispersion as a result of the existence of two different spins per unit cell. We compare our experimental data to numerical results for the specific heat obtained by exact diagonalization and Quantum Monte Carlo simulations for the alternating spin-chain model, using parameters that have been derived from the high-temperature behavior of the magnetic susceptibility. The interchain coupling is included in the numerical treatment at the mean-field level. We observe remarkable agreement between experiment and theory, including the ordering transition, using previously determined parameters. Furthermore, the observed strong effect of an applied magnetic field on the ordered state of MnNi(NO

_{2}

)

_{4}

(en)

_{2}

promises interesting magnetocaloric properties. Full article

(This article belongs to the Special Issue Molecular Magnetism: Modern Trends and Future Perspectives)

► Show Figures

Figure 1

22 pages, 3692 KiB

Open AccessArticle

A Series of Novel Pentagonal-Bipyramidal Erbium(III) Complexes with Acyclic Chelating N₃O₂ Schiff-Base Ligands: Synthesis, Structure, and Magnetism

by Tamara A. Bazhenova, Vyacheslav A. Kopotkov, Denis V. Korchagin, Yuriy V. Manakin, Leokadiya V. Zorina, Sergey V. Simonov, Ilya A. Yakushev, Vladimir S. Mironov, Alexander N. Vasiliev, Olga V. Maximova and Eduard B. Yagubskii

Molecules 2021, 26(22), 6908; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26226908 - 16 Nov 2021

Cited by 9 | Viewed by 2492

Abstract

A series of six seven-coordinate pentagonal-bipyramidal (PBP) erbium complexes, with acyclic pentadentate [N₃O₂] Schiff-base ligands, 2,6-diacetylpyridine bis-(4-methoxybenzoylhydrazone) [H₂DAPMBH], or 2,6-diacethylpyridine bis(salicylhydrazone) [H₄DAPS], and various apical ligands in different charge states were synthesized: [Er(DAPMBH)(C₂H₅OH)Cl] (1); [Er(DAPMBH)(H₂O)Cl]·2C₂H₅OH (2); [Er(DAPMBH)(CH₃OH)Cl] (3); [Er(DAPMBH)(CH₃OH)(N₃)] (4); [(Et₃H)N]⁺[Er(H₂DAPS)Cl₂]⁻ (5); and [(Et₃H)N]⁺[Y₀.₉₅Er₀.₀₅(H₂DAPS)Cl₂]⁻ (6). The physicochemical properties, crystal structures, and the DC and AC magnetic properties of 1–6 were studied. The AC magnetic measurements revealed that most of Compounds 1–6 are field-induced single-molecule magnets, with estimated magnetization energy barriers, U_eff ≈ 16–28 K. The experimental study of the magnetic properties was complemented by theoretical analysis based on ab initio and crystal field calculations. An experimental and theoretical study of the magnetism of 1–6 shows the subtle impact of the type and charge state of the axial ligands on the SMM properties of these complexes. Full article

(This article belongs to the Special Issue Molecular Magnetism: Modern Trends and Future Perspectives)

► Show Figures

Graphical abstract

18 pages, 1196 KiB

Open AccessArticle

An Exchange Mechanism for the Magnetic Behavior of Er³⁺ Complexes

by Miroslav Georgiev and Hassan Chamati

Molecules 2021, 26(16), 4922; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26164922 - 13 Aug 2021

Cited by 3 | Viewed by 1787

Abstract

We study the magnetic properties of the erbium based compounds, Na

_{9}

[Er(W

_{5}

_{18}

)

_{2}

] and [(Pc)Er{Pc{N(C

_{4}

_{9}

)

_{2}

}

_{8}

}]

^{\cdot / -}

, in the framework of an effective spin exchange model involving [...] Read more.

We study the magnetic properties of the erbium based compounds, Na

_{9}

[Er(W

_{5}

_{18}

)

_{2}

] and [(Pc)Er{Pc{N(C

_{4}

_{9}

)

_{2}

}

_{8}

}]

^{\cdot / -}

, in the framework of an effective spin exchange model involving delocalized electrons occupying molecular orbitals. The calculations successfully reproduce the experimental data available in the literature for the magnetic spectrum, magnetization and molar susceptibility in dc and ac fields. Owing to their similar molecular geometry, the compounds’ magnetic behaviors are interpreted in terms of the same set of active orbitals and thus the same effective spin coupling scheme. For all three complexes, the model predicts a prompt change in the ground state from a Kramer’s doublet at zero fields to a fully polarized quartet one brought about by the action of an external magnetic field without Zeeman splitting. This alteration is attributed to the enhancement of the effect of orbital interactions over the spin exchange as the magnitude of the external magnetic field increases. Full article

(This article belongs to the Special Issue Molecular Magnetism: Modern Trends and Future Perspectives)

► Show Figures

Figure 1

19 pages, 2774 KiB

Open AccessArticle

Magnetic-Field-Orientation Dependent Thermal Entanglement of a Spin-1 Heisenberg Dimer: The Case Study of Dinuclear Nickel Complex with an Uniaxial Single-Ion Anisotropy

by Azadeh Ghannadan and Jozef Strečka

Molecules 2021, 26(11), 3420; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26113420 - 05 Jun 2021

Cited by 9 | Viewed by 2178

Abstract

The bipartite entanglement in pure and mixed states of a quantum spin-1 Heisenberg dimer with exchange and uniaxial single-ion anisotropies is quantified through the negativity in a presence of the external magnetic field. At zero temperature the negativity shows a marked stepwise dependence on a magnetic field with two abrupt jumps and plateaus, which can be attributed to the quantum antiferromagnetic and quantum ferrimagnetic ground states. The magnetic-field-driven phase transition between the quantum antiferromagnetic and quantum ferrimagnetic ground states manifests itself at nonzero temperatures by a local minimum of the negativity, which is followed by a peculiar field-induced rise of the negativity observable in a range of moderately strong magnetic fields. The rising temperature generally smears out abrupt jumps and plateaus of the negativity, which cannot be distinguished in the relevant dependencies above a certain temperature. It is shown that the thermal entanglement is most persistent against rising temperature at the magnetic field, for which an energy gap between a ground state and a first excited state is highest. Besides, temperature variations of the negativity of the spin-1 Heisenberg dimer with an easy-axis single-ion anisotropy may exhibit a singular point-kink, at which the negativity has discontinuity in its first derivative. The homodinuclear nickel complex [Ni

_{2}

(Medpt)

_{2}

(

μ

-ox)(H

_{2}

_{2}

](ClO

_{4}

)

_{2}

·2H

_{2}

O provides a suitable experimental platform of the antiferromagnetic spin-1 Heisenberg dimer, which allowed us to estimate a strength of the bipartite entanglement between two exchange-coupled Ni

^{2 +}

magnetic ions on the grounds of the interaction constants reported previously from the fitting procedure of the magnetization data. It is verified that the negativity of this dinuclear compound is highly magnetic-field-orientation dependent due to presence of a relatively strong uniaxial single-ion anisotropy. Full article

(This article belongs to the Special Issue Molecular Magnetism: Modern Trends and Future Perspectives)

► Show Figures

Graphical abstract

Journal Menu

Journal Browser

Molecular Magnetism: Modern Trends and Future Perspectives

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (6 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI