Determining the first-order character of La(Fe,Mn,Si)(13)

Article

关键词: ELECTRON METAMAGNETIC LA(FE0.88SI0.12)(13)H-Y;    MAGNETIC ENTROPY CHANGE;    MAGNETOCALORIC PROPERTIES;    SPIN FLUCTUATIONS;    MN;    TEMPERATURE;    TRANSITIONS;    MAGNETOSTRICTION;    FERROMAGNETISM;    COMPOUND;   

DOI  :  10.1103/PhysRevB.95.064411

来源: SCIE

【 摘 要 】

Definitive determination of first-order character of the magnetocaloric magnetic transition remains elusive. Here we use a microcalorimetry technique in two modes of operation to determine the contributions to entropy change from latent heat and heat capacity separately in an engineered set of La(Fe,Mn,Si)(13) samples. We compare the properties extracted by this method with those determined using magnetometry and propose a model-independent parameter that would allow the degree of first-order character to be defined across different families of materials. The microcalorimetry method is sufficiently sensitive to allow observation at temperatures just above the main magnetic transition of an additional peak feature in the low field heat capacity associated with the presence of Mn in these samples. The feature is of magnetic origin but is insensitive to magnetic field, explicable in terms of inhomogeneous occupancy of Mn within the lattice resulting in antiferromagnetic ordered Mn clusters.

【 授权许可】

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