Computational Investigation of the Magnetization Reversal and Magnetoresistive Behaviour of Nanoscale Spin Valve Elements

Abstract

Investigation of the magnetic switching and magnetoresistive behaviour of nanoscale spin valve elements (SVs) of varying physical parameters such as shape, element size, dimensional aspect ratio, and array size is of vital importance for their application in future magnetic memory and storage devices. We have inspected the magnetic switching mechanism and magnetoresistive behaviour of nanoscale SV elements (Co/Cu/Ni80Fe20) and arrays of these elements, with each layer having a thickness of 10 nm and rectangular and elliptical shapes with varying lateral aspect ratios (ARs) and varying interelement spacing for the arrays, by finite difference method-based micromagnetic simulation. We observe that the elements with higher AR show the Ni80Fe20 and Co layers forming antiparallel states in the plateau, similar to synthetic antiferromagnets. For lower AR, more complex quasi-uniform magnetic microstates are observed, which are even more intricate for elliptical elements. The elliptical elements with an AR of 1.25 show coherent and predictable magnetic switching behaviour, demonstrating their appropriateness for integration into magnetic memory devices. We observe a gradual increase in magnetoresistance (MR%) with the increase in AR and the decrease in interelement spacing. The magnetic flux density experiences a reduction with an increase in the inter-elemental spacing.