The tunable spin reorientation, temperature induced magnetization reversal, and spontaneous exchange bias effect of Sm0.7Y0.3Cr1−xGaxO3

Abstract

In this work, we investigated the temperature dependent magnetic properties of SmCrO₃ by codoping nonmagnetic ions at Sm- and Cr-sites. The spin reorientation from Γ₄ to Γ₂ is tuned and the transition temperature T_SR is improved dramatically to near the liquid nitrogen temperature by Ga ion doping, which would be helpful to achieve its application in temperature sensitive spintronic devices and magnetic switching devices. An intrinsic temperature induced magnetization reversal effect from positive to negative under zero-field-cooling conditions is induced as well and its reversal evolution is strongly dependent upon doping. Moreover, the zero-field-cooling exchange bias effect still exists and shows a positive exchange bias field although it is suppressed with increase of doping concentration. Under the influence of doping nonmagnetic ions, lattice distortion is induced to some extent and the magnetic interactions of Cr–Cr and Sm–Cr are predominantly diluted, realizing control of the above phenomena. Those phenomena are discussed and successfully explained by considering the magnetic exchange interaction competitions including the isotropic, antisymmetric (or Dzyaloshinskii–Moriya interaction), and anisotropic superexchange interactions.