Magnetocaloric effect in La 0.7 Nd x Ba (0.3-x) MnO 3 (x = 0, 0.05, 0.1) perovskite manganites

Abstract

We have synthesized La 0.7 Nd x Ba (0.3-x) MnO 3 (x = 0, 0.05, 0.1) perovskite manganites by using sol-gel method and investigated structure, magnetic and magnetocaloric properties. Structural analysis revealed that La 0.7 Ba 0.3 MnO 3 and La 0.7 Nd 0.05 Ba 0.25 MnO 3 have cubic and La 0.7 Nd 0.1 Ba 0.2 MnO 3 rhombohedral structure. The Curie temperature of the samples decreased with increasing Nd content and equals to 303, 293 and 257 K for x = 0, 0.05, 0.1, respectively. We present experimentally by using magnetization isotherms and heat-capacity measurements that room temperature magnetic refrigeration is successfully achieved for La 0.7 Nd 0.05 Ba 0.25 MnO 3 structure by tuning the Mn 3+ to Mn 4+ ratio. Additionally, zero-field and field-dependent heat-capacity measurements were compared to investigate the accuracy of the value of the adiabatic temperature-change. © 2017