Thin Amorphous Films for Power Magnetic Components

We provide an analysis of the high frequency (1 - 10 MHz) experimental loss data of thin film magnetic material with a goal to provide guidance in achieving better efficiency of thin film magnetic devices. We show that in the case of ultra-thin crystalline material (permalloy), the loss is dominated by classical eddy current loss, which may be difficult to reduce by any known techniques. However, in case of ultra-thin amorphous films we show that the loss is dominated by excess eddy current loss component. This loss component can be suppressed by the well known method of induced anisotropy and, thus, we suggest the use of ultra-thin amorphous thin films with an induced anisotropy to improve the efficiencies of thin film magnetic devices. We also briefly review devices that have been built using thin films materials as well as other quasi-planar technologies. New experimental work is suggested.