Tunneling anisotropic magnetoresistance in epitaxial CoFe/n-GaAs junctions

Magnetic and transport properties of a fully epitaxial CoFe/n-GaAs junction were investigated. The CoFe film grown on the GaAs showed strong magnetic anisotropy in which uniaxial anisotropy with an easy axis of [11^^-0] dominated with a slight cubic anisotropy having easy axes of [110] and [11^^-0] superimposed. Tunneling anisotropic magnetoresistance (TAMR) was observed at 4.2 K in the CoFe/n-GaAs junction. Angular dependence of the tunnel resistance showed uniaxial-type anisotropic tunnel resistance between the [110] and [11^^-0] directions in the (001) plane that varied strongly with a bias voltage. The observed TAMR effect can be explained by the anisotropic electronic structure due to Rashba and Dresselhaus spin-orbit interactions. (c) 2009 American Institute of Physics.