Enhancing and decoupling magnetic anisotropy and tunnel magnetoresistance in CoFe2O4/MgO bilayers via swift heavy ion irradiation

Abstract

Magnetic tunnel junctions (MTJs) formed by CoFe2O4 and MgO are key components to form memory elements in magnetic random access memory (MRAM) for high-density data storage applications. The performance of MRAM devices relies on key properties such as magnetic anisotropy (MA) and tunnel magnetoresistance (TMR), which play a significant role in determining data retention, write speed and device stability. Therefore, a thorough understanding of the relation between properties is crucial for optimizing the performance of MTJ-based memory devices. These properties have been seen to improve by the effects of Swift heavy ion (SHI) irradiation through improved structural and interfacial electronic effects. This study investigates the effects of Swift heavy ion (SHI) irradiation on magnetic anisotropy and tunnel magnetoresistance properties of CoFe2O4/MgO magnetic bilayer. The magnetic bilayers were fabricated and irradiated using radio frequency (RF) magnetron sputtering technique. The magnetic properties of the MTJ were analyzed through X-ray magnetic circular dichroism (XMCD) and element specific hysteresis curves at Fe L-edge and Co L-edge, measured along in-plane and out-of-plane axis for both the irradiated and pristine samples. The results show SHI irradiated thin films have enhanced magnetic anisotropy and transport properties of the thin film. The study also suggests an inverse relation between the two phenomenon, which will be important in making MTJs with high magnetic anisotropy and TMR. This contribution in understanding the enhancement of magnetic and transport properties by SHI irradiation on MTJ is critical in advancing MTJ technology for spintronic applications.