Non-volatile memory characteristics of submicrometre hall structures fabricated in epitaxial ferromagnetic MnAl films on GaAs

Hall-effect structures with submicrometre linewidths (<0.3 mu m) have been fabricated in ferromagnetic thin films of Mn_0.60Al_0.40 which are epitaxially grown on a GaAs substrate. The MnAl thin films exhibit a perpendicular remanent magnetisation and an extraordinary Hall effect with square hysteretic behaviour. The presence of two distinct stable readout states demonstrates the potential of using ultrasmall ferromagnetic volumes for electrically addressable, non-volatile storage of digital information.