Abstract:
An inexpensive perovskite type (REMIX)0.67Sr0.33MnO3 compound is synthesized via solid state method
using mixed rare earth oxide precursor derived from monazite sand. Rietveld refinement of X-ray powder
diffraction patterns confirms the compound is a mixture of rare earth manganites which is the major phase and CeO2 as the secondary phase. The compound shows a second order ferromagnetic to paramagnetic transition near room temperature and exhibits a magnetic entropy change (-DSM) of 3.28 J kg 1 K 1 with a relative cooling power (RCP) of 120 J kg 1 and an adiabatic temperature change (DTad) of 2.11 K at 310 K under 50 kOe magnetic field. The Debye temperature of the compound is found to be 543 K and room temperature thermal conductivity is 4.26 W m 1 K 1. The temperature variation of electrical resistivity shows a metal to insulator transition around 180 K, which gets shifted towards higher temperature upon the application of magnetic field. The compound shows a large value of DSM and this work makes an endeavor to develop low–cost materials for the magnetic refrigeration applications near the room temperature.
