Structural transformation, magnetization reversal and magnetic switching in Cr doped GdMnO3 perovskite

Abstract

In this paper, the effect of Cr doping on the structure and magnetic properties of a GdMnO₃ (GMO) perovskite is reported. The X-ray diffraction (XRD) patterns show a structural transformation from O′ to O type orthorhombic symmetry after doping 50 at% Cr into GdMnO₃ (GMCO), which is confirmed by the Rietveld refinement fitting. Furthermore, the Jahn–Teller distortion (J–T) factor estimated from XRD is found to decrease, and this agrees well with the value estimated from X-ray absorption fine structure (EXAFS) studies. The temperature-dependent magnetization shows an enhancement in Néel temperature (T_N) from ∼42 K in GMO to ∼140 K together with magnetization reversal (MR) and a spin reorientation transition (T_SR) in GMCO. At 15 K, magnetic switching behavior is discovered upon varying the applied magnetic field from 500 to 2000 Oe. Such unusual magnetic behavior is explained on the basis of magnetic interactions between Gd³⁺, Mn³⁺, and Cr³⁺ ions. The structural and magnetic properties of these perovskites have made possible more applications relating to magnetic switching and spintronic devices.