Study of the sign change of exchange bias across the spin reorientation transition in Co(Cr1−xFex)2O4 (x = 0.00–0.125)

Abstract

We present the evolution of novel phenomena of magnetic compensation effect, exchange bias (EB) effect and the field induced anomalies in ‘’ substituted multiferroic compound . A few percent of ‘’ substitution for ‘’ in results in the reversal of field cooled magnetization under low applied fields below compensation temperature Tcomp. Further, increase in the field leads to the spin reorientation transition (TSR). Signature of EB in a narrow temperature window in the vicinity of TSR and its sign change across TSR is observed. Magnitude of EB depends on the amount of compensation and rigidity of the spin reorientation. We also notice the appearance of positive EB below the lock-in transition (TL). Presence of unidirectional anisotropy developed in the commensurate spin-spiral below TL could be responsible for the appearance of EB below TL.