Optical property of Fe/GaAs(0 0 1) hybrid structures grown by molecular beam epitaxy

We report on the epitaxy of Fe thin films on GaAs(0 0 1) using molecular beam epitaxy with two new growth methods which optimize the interface quality for spin injection. These methods make use of low temperature deposition at −150°C and/or of an ultra-thin Al interlayer, respectively. High quality, epitaxial single crystal Fe films have been obtained using these methods. The Fe films have easy axes along [1 1 0] with square hysteresis loops and hard axes along View the MathML source. Photoluminescence of an Al0.3Ga0.7As/GaAs quantum well in close proximity to the Fe film is used to determine the quality of the Fe/GaAs interface.