Nanogranular Co-Fe-Al-O sputtered thin films for magnetoelastic device applications in the GHz frequency range

Abstract

Co-Fe-Al-O nanogranular thin films for magnetoelastic device applications in the GHz frequency range are fabricated by RF-magnetron sputtering under an Ar + O-2 atmosphere. A very large resistivity up to 400 muOmega cm, a saturation magnetization (4piM(S)) of 16 kG and an anisotropy field of 45 Oe are consistently obtained, resulting in excellent high-frequency magnetic properties, such as a high ferromagnetic resonance frequency of 2.3 GHz combined with a large real part of permeability of 315. A saturation magnetostriction of 45 ppm is achieved at a magnetic field as low as 20 Oe. (C) 2003 Elsevier B.V. All rights reserved.