Occurrence of Mixed Phase in \(\text {Bi}_{0.5}\text {Sr}_{0.5}\text {Mn}_{0.9}\text {Cr}_{0.1}\text {O}_3\) Bulk Sample: Electron Paramagnetic Resonance and Magnetization Studies

Abstract

We study the effects of 10% Cr substitution in Mn sites of Bi\(_{0.5}\)Sr\(_{0.5}\)MnO\(_3\) on the antiferromagnetic (AFM) (\(T_{\text {N}} \sim \) 110 K) transition using structural, magnetic and electron paramagnetic resonance (EPR) techniques. Field cooled (FC) and zero field cooled (ZFC) magnetization measurements done from 400 K down to 4 K show that the compound is in the paramagnetic (PM) phase till 50 K where it undergoes a transition to a short-range ferromagnetic phase (FM). Electron paramagnetic resonance measurements performed in the temperature range of 300 K to 80 K conform with the magnetization measurements as symmetric signals are observed owing to the paramagnetic phase. Below 80 K, signals become asymmetric. Electron paramagnetic resonance intensity peaks at \(\sim \) 110 K, the decreasing intensity below this temperature confirming the presence of antiferromagnetism. We conclude that below 50 K the magnetization and EPR results are consistent with a cluster glass phase of BSMCO, where ferromagnetic clusters coexist with an antiferromagnetic background.