Article ID Journal Published Year Pages File Type
1809504 Physica B: Condensed Matter 2014 6 Pages PDF
Abstract

La0.67Ba0.23Ca0.1MnO3 doped with different amounts of yttrium (Y) result in the series La0.67−xYxBa0.23Ca0.1MnO3 (LYBCMO) (x  =0.00, 0.05, 0.10 and 0.15) which was synthesized by conventional solid state ceramics route. All samples show a rhombohedral structure (space group R3¯c) at room temperature. A transition from a paramagnetic to a ferromagnetic phase is observed at Curie temperature, TC. It has been found that the substitution of Y on the La site causes a reduction in TC. Analyses of crystallographic data suggested a strong correlation between structural properties and magnetism. As an example, a relationship between the distortion of MnO6 octahedron and the reduction in Curie temperature. The magnetic entropy change (−ΔS)m was estimated from isothermal magnetization curves. It decreases from 4.91 J/kg K at 350 k (x=0.00) to 4.14 J/kg K at 289 K (x  =0.15) with the increase of Y content under μ0H=5T. The relative cooling power (RCP) is found to be 365 J/kg for La0.67Ba0.23Ca0.1MnO3 and 288 J/kg for La0.52Y0.15Ba0.23Ca0.1MnO3 in the magnetic field change of 5 T. From these results, La0.67−xYxBa0.23Ca0.1MnO3 materials are strongly suggested for use as active refrigerants in magnetic refrigeration technology at near room temperature.

Related Topics
Physical Sciences and Engineering Physics and Astronomy Condensed Matter Physics
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