Interwoven spin-reorientation and exchange bias in Nd1-xPrxCrO3

Abstract

We report the systematic study of structural and magnetic properties of Nd1-xPrxCrO3 (0.0 ≤x≤ 0.30) perovskites. The XPS measurements confirm desired Pr (3+) valence state for the samples. The significant magnetization value with increased antiferromagnetic ordering (TN) and decreased spin-reorientation transition (TSR) is observed with Pr substitution. The enhanced weak ferromagnetism by Pr3+ presence dilutes Nd and Cr interactions, which finally vanishes TSR at maximum substitution. The Griffiths phase is observed in the substituted samples. A noticeable exchange bias (EB) effect is found for all samples. However, for the samples with higher Pr content, where spin-reorientation is suppressed, we observed the sharp increase in the EB field at 5 K (T < TSR). Interestingly, at 100 K (T > TSR), the substitution dependence of the EB field and magnetization link with the changes in the Cr-O bond length. Furthermore, the CrO6 octahedral Raman modes below TN mark spin-phonon coupling. The evolution of the magnetic phase diagram is given. The study sheds light on tuned spin-reorientation, EB effect, and structural features in Nd1-xPrxCrO3 compounds.