Enhanced Exchange Bias Effect by Modulating Relative Ratio of Magnetic Ions in Y2Co2−xMnxO6 (x = 1.0–1.9)

Abstract

It has recently been reported that the exchange bias (EB) phenomenon in double‐perovskite Y2CoMnO6 ceramic arises from additional antiferromagnetic (AFM) clusters formed by the anti‐sites of ionic disorders in the dominant ferromagnetic (FM) phase. To extensively examine the role of ionic orders and versatile magnetic interactions, we measure the magnetic properties of Y2Co2 − xMnxO6 (x = 1.0–1.9) compounds with different relative ratios of the magnetic ions. Upon increasing the ratio of Mn ions, the FM transition temperature is gradually lowered with a greatly enhanced EB effect for x ≥ 1.4. The measurement of heat capacity and AC magnetic susceptibility in the compound with x = 1.5 suggests the formation of magnetic cluster‐glass state from short‐range FM order with comparable AFM clusters generated by the formation of Mn3+–O2−–Mn3+ bonds. The dependence of the EB effect on the cooling field reveals the maximum EB field at 2 K to be HEB = 3.19 kOe. The large EB effect originates from the adjusted proportions of FM and AFM phases and the improved interfacial pinning of exchange coupling in the cluster‐glass state. Our results, based on intricate magnetic correlations and phases, provide essential clues for exploring suitable ceramic compounds for magnetic functional applications.