Beam parameter effects on magnetic properties of sputtered amorphous Fe40Ni40B15Si5 and Fe40Co40B15Si5 films

Abstract

Amorphous films were deposited onto fused quartz by ion beam sputter deposition to examine possible alternatives to existing polycrystalline microwave materials. Ion beam parameters were systematically varied to determine the dependence of film magnetic properties on beam conditions. Chemical composition of representative films were confirmed using Auger electron spectroscopy and Rutherford backscattering spectroscopy. Amorphousness was confirmed by x-ray diffraction analysis, and film thickness was determined by surface profilometer trace. Film magnetic properties were measured by vibrating sample magnetometer and ferromagnetic resonance techniques. It was found that films deposited under higher beam energies showed the lowest coercivities and anisotropy fields. Saturation magnetization values remained largely unaffected by beam parameter variation. Evidence suggests vacuum base pressure plays a significant role in film magnetic properties. Improvement of the films’ soft magnetic properties with increased beam energy may be attributed to reductions in trapped impurities resulting from increased deposition rates. The resulting films display promising properties for microwave magnetic applications.