Anomalous RF sputtering in a high magnetic field: the effect of high magnetic fields on the growth of Fe-Si-O films

We have investigated anomalous RF sputtering in a high magnetic field, and the effects of high magnetic fields on the microstructures and magnetic pro perties of Fe-Si-O films. Using a specially designed sputtering apparatus w hose chamber can be set in a 6 T liquid helium-free superconducting magnet, Fe-Si-O films were successfully deposited in Ar + O-2 mixture. Three typic al sample appearances, hole-at-center, phase-separation and hybridization w ere obtained for the Fe-Si-O films prepared in the low oxygen-argon flow ra tio (<1.0%), low magnetic field (<1.0 T) regime, indicating that the distri bution of plasma is strongly influenced by a magnetic field, resulting in a n inhomogeneous spatial distribution of sputtered atoms. In the high oxygen -argon flow ratio (> 2.0%), high magnetic field (> 2.0 T) regime, strong (1 10) orientation of Fe3O4 grains and larger remanence and coercivity measure d in the direction normal to the film plane appeared in the Fe-Si-O films, indicating that the high magnetic fields not only orient the Fe-Si-O film b ut also induce remarkable perpendicular magnetic anisotropy during the depo sition. (C) 2001 Elsevier Science B.V. All rights reserved.