Formation of ferromagnetic submicron particles of MnAs and MnGa on GaAs substrates by ion implantation

Submicron room-temperature ferromagnets of MnAs and MnGa have been fabricat ed on GaAs semiconductor substrates by Mn+ ion implantation and subsequent heat treatment at 900 degrees C under a controlled atmosphere. MnAs and MnG a particles are formed under nitrogen gas and forming (90%N-2,10%H-2) gas a tmospheres, respectively. Their structural, magneto-optical and magnetic pr operties are characterized by superconducting quantum interference. device magnetometry, magnetic circular dichroism spectroscopy, transmission electr on microscopy, and atomic and magnetic force microscopies. The MnAs precipi tates grow epitaxially on GaAs substrates and show an in-plane uniaxial mag netic anisotropy.