A BROAD-BAND METHOD FOR MEASURING THE COMPLEX PERMEABILITY OF THIN SOFT-MAGNETIC FILMS

An automated method for measuring the complex permeability of anisotro pic thin magnetic films over a broad frequency band is described. The method is based on the measurement, by a network analyser, of scatteri ng matrix elements of a rectangular coaxial transmission line loaded b y the sample. The sample is deposited onto a nonmagnetic substrate, so that the measured S parameters are characteristic of the total transv erse section of the line. To relate those measured values to thin-film permeability, a numerical resolution of Laplace's equation in a quasi -TEM approximation is used. Results showing the complex permeability o f CoZr thin films versus frequency for different orientations of the m agnetic exciting field, obtained by this method, are presented.