Next Issue
Volume 8, January
Previous Issue
Volume 7, November
 
 

Magnetochemistry, Volume 7, Issue 12 (December 2021) – 10 articles

Cover Story (view full-size image): The multicaloric effect is defined as the adiabatic temperature change in multiferroic materials induced by the application of an external excitation such as an electric field, magnetic field or mechanical stress, as first proposed by Vopson in 2012. Depending on the operating conditions, the temperature changes can be positive or negative, leading to the possible commercialisation of the multicaloric effect in solid-state heating or cooling systems. The featured cover article briefly reviews the already known solid-state cooling process based on the multicaloric effect, and it describes its new possible application to solid-state heating. The cover image shows the schematic diagrams of the multicaloric cooling and heating cycles, their corresponding thermodynamic cycles and the generalised multicaloric effect equation governing these processes. View this paper
  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Section
Select all
Export citation of selected articles as:
12 pages, 3540 KiB  
Review
Recent Advances in the Catalytic Applications of Lanthanide-Oxo Clusters
by Weiming Huang, Qingxin Liu, Wanmin Chen, Min Feng and Zhiping Zheng
Magnetochemistry 2021, 7(12), 161; https://doi.org/10.3390/magnetochemistry7120161 - 20 Dec 2021
Cited by 11 | Viewed by 3301
Abstract
Lanthanide-oxo/hydroxo clusters (LOCs) in this mini-review refer to polynuclear complexes featuring a polyhedral metal-oxo/hydroxo cluster core of lanthanide ions exclusively or with coexisting 3d metal ions. We summarize herein the recent works using this unique family of cluster complexes for catalysis; this [...] Read more.
Lanthanide-oxo/hydroxo clusters (LOCs) in this mini-review refer to polynuclear complexes featuring a polyhedral metal-oxo/hydroxo cluster core of lanthanide ions exclusively or with coexisting 3d metal ions. We summarize herein the recent works using this unique family of cluster complexes for catalysis; this aspect of research stands in stark contrast to their extensively studied synthetic and structural chemistry as well as the much-researched magnetic properties. Following a brief introduction of the synthetic strategies for these clusters, pertinent results from available literature reports are surveyed and discussed according to the types of catalyzed reactions. Particular attention was paid to the selection of a cluster catalyst for a specific type of reactions as well as the corresponding reaction mechanism. To the end, the advantages and challenges in utilizing LOCs as multifunctional catalysts are summarized, and possible future research directions are proposed. Full article
(This article belongs to the Special Issue Advances in Lanthanide Coordination Chemistry)
Show Figures

Figure 1

7 pages, 1244 KiB  
Article
Microstructure and Magnetic Properties of Ce14Fe78Co2B6 Nanopowders Prepared by Ball Milling at Low Temperature
by Marian Grigoras, Mihaela Lostun, Firuta Borza, Marieta Porcescu, George Stoian and Nicoleta Lupu
Magnetochemistry 2021, 7(12), 160; https://doi.org/10.3390/magnetochemistry7120160 - 10 Dec 2021
Viewed by 2439
Abstract
Ce14Fe78Co2B6 nanopowders with hard-magnetic properties have been successfully prepared by ball milling at low temperatures in liquid nitrogen. The morphology, structure, and magnetic properties of Ce14Fe78Co2B6 powders have been [...] Read more.
Ce14Fe78Co2B6 nanopowders with hard-magnetic properties have been successfully prepared by ball milling at low temperatures in liquid nitrogen. The morphology, structure, and magnetic properties of Ce14Fe78Co2B6 powders have been investigated using scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometry, respectively. It was found that powder ball milling at low temperature in liquid nitrogen, has the advantage that the oxidation of powders is inhibited and the particles rapidly reach nanometric dimensions. In comparison to the Ce14Fe78Co2B6 powders prepared by ball milling at room temperature, the powders milled at low temperature present a more uniform particle size and no rare-earth oxides, which leads thus to remarkable magnetic properties. The nanocrystalline Ce14Fe78Co2B6 powders with optimum characteristics, prepared at low temperature, have the size of 153 nm or less, present a coercivity of 5.1 kOe, and a saturation magnetization of 113 emu/g after milling for 6 h at low temperature. Low temperature milling may become a promising technique for the fabrication of high performance powders used for permanent magnets preparation. Full article
(This article belongs to the Special Issue Advances in Magnetic Microspheres)
Show Figures

Figure 1

12 pages, 3900 KiB  
Article
Structural, Electronic and Magnetic Properties of Mn2Co1-xVxZ (Z = Ga, Al) Heusler Alloys: An Insight from DFT Study
by Fatima Abuova, Talgat Inerbaev, Aisulu Abuova, Nurpeis Merali, Nurgul Soltanbek, Gulbanu Kaptagay, Marina Seredina and Vladimir Khovaylo
Magnetochemistry 2021, 7(12), 159; https://doi.org/10.3390/magnetochemistry7120159 - 8 Dec 2021
Cited by 3 | Viewed by 3045
Abstract
Structural, electronic, and magnetic properties of Mn2Co1-xVxZ (Z = Ga, Al, x = 0, 0.25, 0.5, 0.75, 1) Heusler alloys were theoretically investigated for the case of L21 (space group Fm3¯m), [...] Read more.
Structural, electronic, and magnetic properties of Mn2Co1-xVxZ (Z = Ga, Al, x = 0, 0.25, 0.5, 0.75, 1) Heusler alloys were theoretically investigated for the case of L21 (space group Fm3¯m), L21b (L21 structure with partial disordering between Co and Mn atoms) and XA (space group F4¯3m) structures. It was found that the XA structure is more stable at low V concentrations, while the L21 structure is energetically favorable at high V concentrations. A transition from L21 to XA ordering occurs near x = 0.5, which qualitatively agrees with the experimental results. Comparison of the energies of the L21b and XA structures leads to the fact that the phase transition between these structures occurs at x = 0.25, which is in excellent agreement with the experimental data. The lattice parameters linearly change as x grows. For the L21 structure, a slight decrease in the lattice constant a was observed, while for the XA structure, an increase in a was found. The experimentally observed nonlinear behavior of the lattice parameters with a change in the V content is most likely a manifestation of the presence of a mixture of phases. Almost complete compensation of the magnetic moment was achieved for the Mn2Co1-xVxZ alloy (Z = Ga, Al) at x = 0.5 for XA ordering. In the case of the L21 ordering, it is necessary to consider a partial disorder of atoms in the Mn and Co sublattices in order to achieve compensation of the magnetic moment. Full article
(This article belongs to the Section Spin Crossover and Spintronics)
Show Figures

Figure 1

18 pages, 2918 KiB  
Review
Polarized Neutron Diffraction: An Excellent Tool to Evidence the Magnetic Anisotropy—Structural Relationships in Molecules
by Dominique Luneau and Béatrice Gillon
Magnetochemistry 2021, 7(12), 158; https://doi.org/10.3390/magnetochemistry7120158 - 6 Dec 2021
Cited by 5 | Viewed by 2535
Abstract
This publication reviews recent advances in polarized neutron diffraction (PND) studies of magnetic anisotropy in coordination compounds comprising d or f elements and having different nuclearities. All these studies illustrate the extent to which PND can provide precise and direct information on the [...] Read more.
This publication reviews recent advances in polarized neutron diffraction (PND) studies of magnetic anisotropy in coordination compounds comprising d or f elements and having different nuclearities. All these studies illustrate the extent to which PND can provide precise and direct information on the relationship between molecular structure and the shape and axes of magnetic anisotropy of the individual metal sites. It makes this experimental technique (PND) an excellent tool to help in the design of molecular-based magnets and especially single-molecule magnets for which strong uniaxial magnetic anisotropy is required. Full article
(This article belongs to the Special Issue From Magnetic Anisotropy to Molecular Magnets: Theory and Experiments)
Show Figures

Figure 1

15 pages, 5143 KiB  
Article
Electrochemical, Electrocatalytic, and Magnetic Properties of Vanadium-Containing Polyoxometalates
by Joseph Dika Manga, Anne-Lucie Teillout, Eric Rivière, Pedro de Oliveira and Israël Martyr Mbomekallé
Magnetochemistry 2021, 7(12), 157; https://doi.org/10.3390/magnetochemistry7120157 - 3 Dec 2021
Cited by 1 | Viewed by 2598
Abstract
Mono-substituted vanadium-containing Dawson-type polyoxometalates having the general formula α1-[VIVW17X2O62]8− and α2-[VIVW17X2O62]8−, with X = As or P, were synthesised and [...] Read more.
Mono-substituted vanadium-containing Dawson-type polyoxometalates having the general formula α1-[VIVW17X2O62]8− and α2-[VIVW17X2O62]8−, with X = As or P, were synthesised and subject to a comprehensive electrochemical study comprising the pH dependency. These POMs exhibit an electrocatalytic behaviour towards the oxidation of thiols (namely cysteine), rendering them interesting species for mimicking oxidative stress situations, at physiological pH values. The efficiency of the electro-oxidation was assessed with thiols of different nature, and the substrate that responded best was used to compare the electrocatalytic capabilities of the POM series. The magnetic behaviour of these POMs was also evaluated and compared to their analogues, α1- and α2-[VVW17X2O62]7− (X = As or P), at low temperatures and showed, as expected, a paramagnetic behaviour of VIV based compounds. Full article
(This article belongs to the Special Issue Paramagnetic Metal Ion-Containing Polyoxometalates)
Show Figures

Figure 1

8 pages, 1759 KiB  
Article
Ferromagnetic Resonance of a [GeTe/Sb2Te3]6/Py Superlattice
by Satoshi Sumi, Yuichiro Hirano, Hiroyuki Awano and Junji Tominaga
Magnetochemistry 2021, 7(12), 156; https://doi.org/10.3390/magnetochemistry7120156 - 26 Nov 2021
Cited by 2 | Viewed by 2267
Abstract
A [GeTe/Sb2Te3] superlattice is known as a topological insulator. It shows magnetic responses such as magneto-optical effect, magneto resistance, magneto capacitance, and so on. We have reported that [GeTe/Sb2Te3] superlattice film has a large spin–orbit [...] Read more.
A [GeTe/Sb2Te3] superlattice is known as a topological insulator. It shows magnetic responses such as magneto-optical effect, magneto resistance, magneto capacitance, and so on. We have reported that [GeTe/Sb2Te3] superlattice film has a large spin–orbit interaction using a spin pumping method of a [GeTe/Sb2Te3]/Py superlattice. In this paper, we demonstrate a ST-FMR (spin transfer torque ferromagnetic resonance) of the [GeTe/Sb2Te3]6/Py superlattice, compared with a W/Py bilayer. The superlattice film showed a large resonance signal with a symmetric component. The ratio of symmetric components (S) to anti-symmetric (A) components (S/A) was 1.4, which suggests that the superlattice exhibits a large spin Hall angle. The [GeTe/Sb2Te3] superlattice will be suitable as a hetero-interface material required for high performance spintronics devices in future. Full article
(This article belongs to the Section Spin Crossover and Spintronics)
Show Figures

Figure 1

9 pages, 1223 KiB  
Article
Magnonic Crystal with Strips of Magnetic Nanoparticles: Modeling and Experimental Realization via a Dip-Coating Technique
by Zorayda Lazcano-Ortiz, Cesar L. Ordóñez-Romero, Jorge Luis Domínguez-Juárez, Guillermo Monsivais, Rafael Quintero-Torres, Daniel Matatagui, José Roberto Fragoso-Mora, Naser Qureshi and Oleg Kolokoltsev
Magnetochemistry 2021, 7(12), 155; https://doi.org/10.3390/magnetochemistry7120155 - 26 Nov 2021
Cited by 4 | Viewed by 2502
Abstract
In this article, we describe a magnonic crystal formed by magnetite nanoparticles. The periodic strip-like structure of the nanoparticles was fabricated on the surface of thin yttrium iron garnet single-crystal film grown on a gallium–gadolinium garnet substrate via dip-coating techniques. It was shown [...] Read more.
In this article, we describe a magnonic crystal formed by magnetite nanoparticles. The periodic strip-like structure of the nanoparticles was fabricated on the surface of thin yttrium iron garnet single-crystal film grown on a gallium–gadolinium garnet substrate via dip-coating techniques. It was shown that such periodic structure induces the formation of the bandgaps in the transmission spectra of magnetostatic surface spin-waves (MSSW). The structure was simulated by the transfer matrix method. Spin-wave detection has been carried out by using a pair of microwave antennas and a vector network analyzer. Full article
Show Figures

Figure 1

7 pages, 1065 KiB  
Communication
Solid-State Heating Using the Multicaloric Effect in Multiferroics
by Melvin M. Vopson, Yuri K. Fetisov and Ian Hepburn
Magnetochemistry 2021, 7(12), 154; https://doi.org/10.3390/magnetochemistry7120154 - 24 Nov 2021
Cited by 2 | Viewed by 2697
Abstract
The multicaloric effect is defined as the adiabatic reversible temperature change in multiferroic materials induced by the application of an external electric or magnetic field, and it was first theoretically proposed in 2012. The multicaloric effects in multiferroics, as well as other similar [...] Read more.
The multicaloric effect is defined as the adiabatic reversible temperature change in multiferroic materials induced by the application of an external electric or magnetic field, and it was first theoretically proposed in 2012. The multicaloric effects in multiferroics, as well as other similar caloric effects in single ferroics, such as magnetocaloric, elastocaloric, barocaloric, and electrocaloric, have been the focus of much research due to their potential commercialization in solid-state refrigeration. In this short communication article, we examine the thermodynamics of the multicaloric effect for solid-state heating applications. A possible thermodynamic multicaloric heating cycle is proposed and then implemented to estimate the solid-state heating effect for a known electrocaloric system. This work offers a path to implementing caloric and multicaloric effects to efficient heating systems, and we offer a theoretical estimate of the upper limit of the temperature change achievable in a multicaloric cooling or heating effect. Full article
(This article belongs to the Special Issue Multiferroic Materials 2021)
Show Figures

Figure 1

11 pages, 3107 KiB  
Article
Syntheses, Structures and Magnetic Properties of M2 (M = Fe, Co) Complexes with N6 Coordination Environment: Field-Induced Slow Magnetic Relaxation in Co2
by Qianqian Yang, Xiao-Lei Li and Jinkui Tang
Magnetochemistry 2021, 7(12), 153; https://doi.org/10.3390/magnetochemistry7120153 - 23 Nov 2021
Cited by 1 | Viewed by 2399
Abstract
Two dinuclear complexes [M2(H2L)2](ClO4)4·2MeCN (M = Co for Co2 and Fe for Fe2) were synthesized using a symmetric hydrazone ligand with the metal ions in an N6 coordination environment. [...] Read more.
Two dinuclear complexes [M2(H2L)2](ClO4)4·2MeCN (M = Co for Co2 and Fe for Fe2) were synthesized using a symmetric hydrazone ligand with the metal ions in an N6 coordination environment. The crystal structures and magnetic properties were determined by single-crystal X-ray diffraction and magnetic susceptibility measurements. The crystal structure study revealed that the spin centers were all in the high-spin state with a distorted octahedron (Oh) geometry. Dynamic magnetic properties measurements revealed that complex Co2 exhibited field-induced single-molecule magnet properties with two-step relaxation in which the fast relaxation path was from QTM and the slow relaxation path from the thermal relaxation under an applied field. Full article
(This article belongs to the Special Issue Magnetic Properties of Metal Complexes)
Show Figures

Figure 1

6 pages, 252 KiB  
Editorial
Perspectives on Molecular Materials—A Tribute to Professor Peter Day
by Lee Martin, Scott S. Turner, John D. Wallis, Hiroki Akutsu and Carlos J. Gómez-García
Magnetochemistry 2021, 7(12), 152; https://doi.org/10.3390/magnetochemistry7120152 - 23 Nov 2021
Viewed by 1920
Abstract
Professor Peter Day FRS was born on 20 August 1938 in Kent (UK) and attended Maidstone Grammar School [...] Full article
Previous Issue
Next Issue
Back to TopTop