Synthesis, characterisation and study of magnetocaloric properties of La_(0.65)Sr_(0.25)K_(0.1)Mn_(1-x)V_xO3

摘要

Polycrystalline perovskite-type manganite La_(0.65)Sr_(0.25)K_(0.1)Mn_(1-x)V_xO3 were prepared by sol-gel method. An X-ray diffraction at room temperature indicated that all samples have a single phase with R-3c space group. Magnetic properties and Curie temperature are measured by superconducting quantum interference device. Magnetization as a function of temperature shows that all samples exhibit a paramagnetic-ferromagnetic phase transition at the Curie temperature. The Curie temperature of samples was increased from 342 K for x=0.00 to 351 K for x=0.15. The magnetic entropy change deduced from the measured magnetization data using Maxwell relation. The maximum magnetic entropy change - ΔS_m corresponding to a 1 T magnetic field variation was found to be 1.0 J/kg K for x=0.05. The style of phase transition of the manganite was distinguished by Banerjee criteria.