Magnetic properties of exchange springs

Abstract

We study the magnetic properties of an exchange spring resulting from an analytical treatment of the bilayer structure for arbitrary material parameters, layer thickness, and interface coupling. We analyze the mechanisms governing the formation of a partial domain wall, and the magnetization reversal under an external field (coercive field of the bilayer). We also discuss energy barriers and the effect of thermal fluctuations on the hysteresis loop and calculate the anisotropic magnetoresistance of the bilayer for the current in plane geometry.