Magnetic and magnetocaloric properties of (La1-x)0.8Ca0.2MnO3 (x=0.05, 0.20) single crystals

The magnetic and magnetocaloric properties of La-deficient manganate single crystals of (La1-x)0.8Ca0.2MnO3 with x=0.05 and 0.20 compositions were investigated. The single crystal with the x=0.05 composition is magnetically more frustrated than that with the x=0.20 composition. The spin-glass transition temperature, Tg, of about 100 K was observed for x=0.05 only. But at x=0.20, a drastic increase in magnetization and Curie temperature was found, as compared to the x=0.05 composition. As a result, for x=0.20, a large magnetic entropy change ΔSM, of about -5.46 J/kg/K for the maximum ΔSM at H=5 T, is associated with the ferromagnetic-paramagnetic transition, which is very applicable for magnetic refrigeration