Oxidation of FePt nanoparticles

Chemically disordered similar to3-7-nm-diameter FePt nanoparticles are synthesized using the airless operation technique based on decomposition of iron pentacarbonyl and reduction of platinum acetylacetonate. The particle solution is then washed and subsequently deposited onto a thermally oxidized Si substrate. Nanoparticle assemblies are formed after solvent evaporation. The samples are heat-treated using rapid thermal annealing at 650degreesC for 30 min, in an atmosphere of Ar gas with less than 1 PPM of O-2. Oxidation has to be avoided to obtain the FePt L1(0) phase. Other crystalline phases such as FePt3 (L1(2)) magnetite Fe3O4, hematite Fe2O3 and FCC Pt are obtained if oxygen is present. (C) 2003 Elsevier B.V. All rights reserved.