Use of 2D logarithmic meshes for a spin-valve sensor

Summary form only given. A new 3-D micromagnetic model has been investigated in predicting the magnetisation processes in the free layer and the pinned layer of a Spin-Valve sensor. Special attention has been paid to how to simplify the model for efficient computation. The present 3-D model for a Spin-Valve sensor utilises a logarithmic mesh distribution. Since there are much larger demagnetising fields at or close to the edges of the sample, there are, correspondingly, greater spatial gradients of magnetisation in these areas. Accordingly, to reduce the required number of elements their sizes are varied across the whole sample, with bigger ones near the centre and smaller ones at the edges. This can reduce the number of elements required which becomes increasingly important for sensor dimensions of the order of tens of microns.