Magnetocaloric properties of transition metal doped Sr2FeMo0.9B0.1O6 (B = Mo, Nb, V, W) double perovskites

摘要

Double perovskite Sr2FeMo0.9B0.1O6 materials doped with fixed amount of various transition metals (B = Mo, Nb, V, W) were synthesized using the solid state reaction method and investigated for their magnetic and magnetocaloric performance. X-ray diffraction profiles of the samples established tetragonal crystal structure with I4/mmm space group in these materials. A strong variation in the magnetization and Curie temperature values was observed in these samples as a result of transition-metal doping. The magnetization measurements and Arrott plots revealed a second order nature of magnetic phase transition in the investigated samples. The magnetocaloric effects in terms of the magnetic entropy change and relative cooling power (RCP) were calculated from the isothermal magnetization curves of the samples. The V-doped sample among the entire batch exhibited a maximum magnetic entropy change of 0.55 J/kg K with an RCP value of 60 J/kg at an applied magnetic field of 2.5 T. The tunability of magnetization, Curie temperature and magnetocaloric features in these materials at low applied field make them very attractive for use in solid state magnetic refrigeration technology.