Exchange bias and antiferromagnetic interfacial exchange coupling in the mixed-spin oxide Li2/7Ni5/7O

Abstract

We present a detailed study on magnetic properties of mixed spin oxide Li2/7Ni5/7O, where small ferromagnetic (FM) clusters (with averaged diameter of ∼18 Å) immersed with an antiferromagnetic (AFM) host. The exchange bias (EB) with shifts of the hysteresis loop along both the field and magnetization axes is found, which is due to the interfacial interaction between the FM clusters and the AFM host. An AFM interfacial exchange coupling is deduced from the exchange interactions between Ni ions. The type and strength of this interfacial exchange interaction are discussed in terms of the EB at low temperature.