Behavior Of Magnetic Entropy Change In Perovskite Ba2-Xlaxfemoo6

The magneto-caloric effect and magnetization behavior have been analyzed in the double-perovskite Ba2-xLaxFeMoO6 compound with the sintering temperature and external magnetic field. Samples were fabricated by the conventional solid-state reaction method. X-ray diffraction measurements revealed that all the samples had a single phase with a cubic structure. The maximum magnetic entropy changes were obtained in the temperature range of 320-330K for all compounds. The Delta S-M is about 0.38 J/kg K for the Ba2-xLaxFeMoO6 (x = 0.2) compound with an external field of 7 kOe, however, Delta S-M is about 2.93 J/kg K with a field of 15 kOe. The value of Delta S-M is increased about eight times with increasing of the external field. The enhancement of the larger magnetic entropy seems to favor the increase of magnetic order, which changes the magnetic part of the entropy of a solid around the magnetic ordering temperature. (C) 2012 American Institute of Physics. [doi:10.1063/1.3679868]