Bipolar switching of magnetization and tunable exchange bias in NdCr1−xMnxO3 (x = 0.0–0.30)

Abstract

Polycrystalline samples of NdCr1−xMnxO3 (x = 0.0–0.30) were prepared by sol-gel method. Samples in the composition range, x = 0.10 to 0.20, exhibit magnetization reversal, and the magnetization compensation temperature (Tcomp) is found to increase from 110 K to 157 K with increase in Mn concentration. The magnetization reversal behavior is explained by considering paramagnetic moments of Nd3+ and Mn3+ ions under the influence of negative internal magnetic field and the canted ferromagnetic component of Cr3+ ions. Bipolar switching of magnetization by varying either the applied field H = 200 Oe to 3000 Oe or temperature through Tcomp is shown. Tunable exchange bias behavior was observed for x = 0.10 to 0.20 samples, and the value of exchange bias field, HEB, could be tuned from −1.6 kOe to +0.39 kOe for x = 0.10 sample. The origin of exchange bias is explained by considering the antiferromagnetic interaction between ferromagnetic component of Cr3+ ions and the paramagnetic components of Nd3+ and Mn3+ ions. The x = 0.30 sample exhibits ferromagnetic like behavior due to super exchange interaction in Cr3+–O2−–Mn3+ networks.