Evolution of Giant Exchange Bias with Ferromagnetic Ordering and Robust Memory Effect by Strain Engineering MoS2 in Weak Antiferromagnetic Gating

Abstract

The emergence of 2D ferromagnetism in MoS2 layers induced by an inherently non-magnetic material like NiOOH is an interesting area of research. This result is of widespread technological importance if additionally associated with magnetic exchange correlations that shows promising memory effects. In this work, we show that a giant exchange bias is housed within a highly strained 2D MoS2 multilayers by interfacing thin weakly antiferromagnetic β-NiOOH phase. The robustness and magnitude of such zero-field-cooled exchange bias emerges from the unique sublattice spin configuration of β-NiOOH which serves as a source of surface uncompensated moments, while highly strained 2D MoS2 acts as active pinning layer in the hybrid. The exchange coupling between the weak antiferromagnetic layer and the adjacent moment induced ferromagnetic layer is strong enough to show near room temperature thermoremnant (TRM) memory effect in the magnetization states which is newly observed for 2D hybrid materials. Upon manifesting vertical type junction, this hybrid material also shows non-volatile electrical bistable states with low operating bias voltage (1.25V) and high ON/OFF ratio (6×102) along with hysteretic magnetoresistance which can be useful in 2D based spintronic applications. First principle calculations also verified such charge transfer interactions at the interace of the hybrid structure.