Near room temperature magnetocaloric properties of Fe substituted La0.67Sr0.33MnO3

Abstract The effect of Fe substitution in the polycrystalline La 0.67 Sr 0.33 MnO 3 has been investigated. Substitution of Fe decreases the Curie temperature of La 0.67 Sr 0.33 MnO 3 from 370 K to near room temperature in x x > 0.3 exhibit a frustrated glassy behaviour, evident from the ZFC and FC magnetization data. The magnetic entropy change calculated from the M – H – T data of x = 0.05 and x = 0.1 show broad peak and the respective values of −Δ S M and RCP are found to be about 2.8 J/kg K, 166 J/kg (at T C = 275 K) and 3.3 J/kg K, 153 J/kg (at T C = 266 K) under a field of 50 kOe. Due to the wider distribution of the magnetic entropy, these two compounds can be used as refrigerants for room temperature magnetic refrigeration applications. The critical behaviour of the two compositions was also estimated from the field dependent magnetic entropy change.