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 fabricated on GaAs semiconductor substrates by Mn/sup +/ ion implantation and subsequent heat treatment at 900/spl deg/C under a controlled atmosphere. MnAs and MnGa particles are formed under nitrogen gas and forming (90%N/sub 2/,10%H/sub 2/) gas atmospheres, respectively. Their structural, magneto-optical and magnetic properties are characterized by superconducting quantum interference device magnetometry, magnetic circular dichroism spectroscopy, transmission electron microscopy, and atomic and magnetic force microscopies. The MnAs precipitates grow epitaxially on GaAs substrates and show an in-plane uniaxial magnetic anisotropy.