Magnetocaloric effect and influence of Fe/Cr disorder on the magnetization reversal and dielectric relaxation in RFe_(0.5)Cr_(0.5)O_3 systems

摘要

We have investigated the structural, magnetic, and dielectric properties of RFe_(0.5)Cr_(0.5)O_3 (R = Nd, Sm, Gd, and Y) compounds. Both structure and magnetic analyses show a Fe/Cr cation disorder, which results in the existence of Fe-rich and Cr-rich clusters. The competition between the moments of the two clusters gives rise to the R-dependent temperature induced magnetization reversal. Interestingly, we also find that the charge carrier hopping in the two clusters leads to two sequential dielectric relaxations in all the samples. In addition, giant magnetocaloric effect with a magnetic entropy change reaching ~29.2 J/kg K was observed with R = Gd.