STUDIES OF MAGNETIC PROPERTIES AND GHz PERMEABILITY OF PURE AMORPHOUS COBALT THIN FILMS

Abstract

Soft Co films deposited by a method which we called the "weak magnetron radio frequency (RF) sputtering" have amorphous structures. The amorphous structure varies with the increasing of P Ar . Static magnetic measurements show that all the films possess high saturation magnetization and a well-defined in-plane uniaxial anisotropy with the easy axis parallel with the applied field. The highest coercivity in the easy axis H ce and in the hard axis H ch is only 20 Oe and 9 Oe, respectively. The sputter pressure P Ar affects essentially the uniaxial anisotropy energy Ku. The GHz permeability of the as-deposited films was measured in the 0.1–5 GHz using the shorted microstrip transmission-line perturbation method. The full-width at half-maximum (FWHM) for the peak in the imaginary part of the permeability at resonance is about 1.3 GHz which is far broader than other FWHM reported.