Structures and magnetic properties of Fe-Si-O films RF-sputtered in a high magnetic field

We have investigated the effects of high magnetic fields on the microstructures and magnetic properties of Fe-Si-O films deposited by RF sputtering. Three typical sample appearances, hole-in-center, phase-separation and hybridization were obtained for the Fe-Si-O films prepared in the oxygen-argon flow ratioV _O2/V _total<1.0%, magnetic fieldB _appl⩽1.0 T regime, indicating that not only the distribution of plasma but also the angular distribution of sputtered atoms are influenced by a high magnetic field. In the oxygen-argon flow ratioV _O2/V _total>2.0%, magnetic fieldB _appl⩾2.0 T regime, strong (110) orientation of Fe₃O₄ grains and larger remanence and coercivity measured in the direction normal to the film plane appeared in the Fe-Si-O films. This result indicates that the high magnetic fields not only orient the Fe-Si-O film but also induce remarkable perpendicular magnetic anisotropy during the deposition.