Effects of deposition and oxidation processes on magnetic and structural properties of iron oxide films

Abstract

Osmium doped (0.75 at.%) iron oxide films were reactively sputter deposited onto Si substrates in an Ar + O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> gas environment. The magnetic and structural properties of the as-deposited films depend critically on deposition process parameters such as O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> flow rate, chamber pressure, substrate temperature, RF power and substrate rotation speed. The deposition process window has been determined for which only the spinel structure was observed. X-ray diffraction indicated films grown at a low O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> flow rate of 3.0 sccm and a substrate temperature of 230°C had more random orientation and a lattice parameter closer to that of the bulk Fe <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> value. This condition produced a high saturation moment of 410 emu/cc. Increasing O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> flow rate induced preferential