Structural and large magnetocaloric properties of La0.67-xYxBa0.23Ca0.1MnO3 perovskites (0 <= x <= 0.15)

作者：Abassi Mounira^*; Dhahri N; Dhahri J; Hlil E K

来源：Physica B: Condensed Matter , 2014, 449: 138-143.

DOI：10.1016/j.physb.2014.05.006

• Perovskite oxides
• Yttrium doping
• Curie temperature
• Magnetic entropy change

La0.67Ba0.23Ca0.1MnO3 duped with different amounts of yttrium (Y) result in the series La0.67-xYxBa0.23 Ca0.1MnO3 (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 R (3) over bar c) at room temperature. A transition from a paramagnetic to a ferromagnetic phase is observed at Curie temperature, T-c. 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 (-Delta S-m) was estimated horn 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 mu H-0 = 5 T. 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 held change of 5 T From these results, La0.67-xYxBa0.23 Ca0.1MnO3 materials are strongly suggested for use as active refrigerants in magnetic refrigeration technology at near room temperature.

• 出版日期2014-9-15