Effect of Sr substitution for Ca on the physical properties in the Nd 0.5Ca0.5MnO3 system

Abstract

The structural, magnetic and magnetocaloric properties of Nd 0.5Ca0.5MnO3 and Nd0.5Ca 0.1Sr0.4MnO3 samples with a fixed ratio of Mn3+/Mn4+=1 have been investigated. The XRD refinement results indicate that both samples are single phase and crystallize in the distorted orthorhombic system with Pbnm space group. Magnetization measurements on the Nd0.5Ca0.5MnO3 sample show a peak at 250 K as a signature of charge ordering. The substitution of Ca by Sr suppresses the charge order state and induces a ferromagnetic phase at low temperature. The magnetic entropy change exhibits positive values around TCO for Nd0.5Ca0.5MnO3 sample and negative values around TC for Nd0.5Ca0.1Sr 0.4MnO3 sample with a maximum of -ΔSM around 260 K. © 2010 IOP Publishing Ltd.