Temperature dependence of magnetization under high fields in Re-based double perovskites

Abstract

We have carried out magnetization measurements in steady magnetic fields up to 30 T in ceramic samples of Re-based double perovskites (A2FeReO6, A2 being Ca2, Sr2 and BaSr, and Sr2CrReO6) in the temperature range from 4 to 300 K. These compounds show non-integer saturation magnetic moment due to the Re orbital contribution and are not completely saturated up to 30 T. The influence of magnetically disordered grain boundaries is revealed, and a model of approximation to saturation is given. The temperature dependence of various magnetic properties is described and compared among the samples.