Oxygen-mediated suppression of twinning in gas-phase prepared FePt nanoparticles
Exp. Tieftemperaturphysik and SFB 445,
Gerhard-Mercator-Universität Duisburg, 47048 Duisburg, Germany
Corresponding author: a email@example.com
Published online: 3 July 2003
We report on the influence of oxygen on the morphology and crystal structure of gas-phase prepared FePt nanoparticles. The particles are prepared by DC-sputtering in an Ar/He gas mixture. Without any oxygen, the obtained particles are predominantly icosahedra. The additional supply of oxygen leads to significant changes in both the crystal structure and morphology of the FePt nanoparticles. With increasing oxygen concentration, we observe the onset of particle agglomeration and a drop of the particle size. In addition, the crystal structure changes from icosahedral to fcc. These results are ascribed to oxygen mediated changes of the surface properties of the FePt nanoparticles such as the surface diffusivity and the surface free energy.
PACS: 81.07.-b – Nanoscale materials and structures: fabrication and characterization / 64.70.Nd – Structural transitions in nanoscale materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003