Molecular Tuning of Giant Exchange Bias at Metal-organic Hybrid Interface

Abstract

Exchange bias (EB) effect is one of the integral part in spintronics applications, which is triggered by a magnetic coupling at the interface between a ferromagnetic (FM) and an antiferromagnetic material (AFM). This effect has been recently received growing attention in a logical memory device because it can act as 'effective magnetic field' without external magnetic field. In this report, we demonstrate the giant EB effect at the interface between antiferromagnetic molecular layers and ferromagnetic thin films. Anisotropic magnetoresistance and SQUID-VSM analyses displays large variation of EB field depending on the stacking molecular layer. The obtained molecular EB field could be as high as ~ 2000 Oe. A density functional theory (DFT) calculation shows correlation between EB bias and interlayer distance. These controllable and tunable organic/inorganic ‘spinterface’ will provide opportunity to realize new functionalities in hybrid magnetic devices.