Metamagnetism

About: Metamagnetism is a research topic. Over the lifetime, 2023 publications have been published within this topic receiving 38108 citations.

Itinerant electron metamagnetism

Abstract: Rigorous conditions for the metamagnetic transitions between the paramagnetic and ferromagnetic states and between the weak ferromagnetic and normal ferromagnetic states are derived. The expressions for the conditions and the critical field are derived in the simple model for an itinerant electron system and for a combined system of localized magnetic moments and itinerant electrons. The results are applied to TiBe2, YCo2, Pd, compounds of rare earth metals and transition metals, Co(S, Se)2, etc. It is explained that TiBe2 and perhaps YCo2 and Pd will not show the metamagnetic transition in consistent with the experimental results.

Synthesis, Structure, and Magnetic Properties of Cobalt(II) Coordination Polymers from a New Tripodal Carboxylate Ligand: Weak Ferromagnetism and Metamagnetism

Abstract: A new tripodal carboxylic ligand, 5-(4-carboxy-phenoxy)-isophthalic acid, readily (cpiaH3) reacts with Co(II) salts in the presence of pyridine-based coligands under solvothermal conditions to afford four different coordination polymers, {Co2(cpia)(OH)(bipy)0.5}n (1), {[Co2(cpia)(OH)(H2O)2]·H2O}n (2), {Co1.5(cpia)(bipyethane)}n (3), and {Co1.5(cpia)(pyridine)2}n (4). All these coordination polymers have been characterized by single crystal X-ray diffraction, IR spectroscopy, thermogravimetry and elemental analysis. The structures of 1 and 2 can be described as a repetition of a tetranuclear core with subtle differences — two tetranuclear cores are shared by an O atom in 2, while no such bridging is present in 1. The structures of 3 and 4, on the other hand, consist of a trinuclear core extending to three-dimensional networks. Variable temperature magnetic susceptibility measurements indicate that 1 exhibits ferromagnetic behavior below 13 K, while 2 shows metamagnetic behavior. These interesting magnetic ...

Thermal transport properties of magnetic refrigerants La(FexSi1−x)13 and their hydrides, and Gd5Si2Ge2 and MnAs

Abstract: La(FexSi1−x)13 and their hydrides exhibit large magnetocaloric effects due to the itinerant-electron metamagnetic transitions in a wide temperature range covering room temperature. Thermal conductivity and diffusivity of La(Fe0.88Si0.12)13 and La(Fe0.88Si0.12)13H1.0 have been investigated, together with those of other candidates for magnetic refrigerants working in the vicinity of room temperature such as Gd, Gd5Si2Ge2 and MnAs. The thermal conductivity in the vicinity of room temperature for La(Fe0.88Si0.12)13H1.0 is larger than that for Gd5Si2Ge2 and MnAs, and almost identical to that for Gd. Furthermore, the thermal diffusivity in the vicinity of room temperature for La(Fe0.88Si0.12)13H1.0 is as large as that for Gd and Gd5Si2Ge2, and larger than that for MnAs. Consequently, La(FexSi1−x)13 and their hydrides are promising as the magnetic refrigerants from the standpoint of thermal transport properties.

Large magnetic entropy change in the metallic antiperovskite Mn3GaC

Abstract: A large positive magnetic entropy change ΔSM is observed in the metallic antiperovskite Mn3GaC near its first-order metamagnetic transition temperature 159 K where the stoichiometric compound transforms from an antiferromagnetic to a canted ferromagnetic state accompanied by a discontinuous volume change of −0.46% without change of symmetry. The unusual field dependence of the ΔSM of Mn3GaC shows a very rapid linear increase from zero to a saturation value within a field interval smaller than 1 T. The broadening of the peak of ΔSM to low temperature with increasing field change creates an ΔSM plateau in the temperature dependence of the MCE, which is of significance for practical application of these materials in the Ericsson-cycle magnetic refrigerator.