IRON LOSS OF THE MULTILAYERED COZRMO CORE

In this paper the iron loss of the magnetic thin-film core is investigated with the intention of applying it to power transformers for high-frequency use. The multilayered CoZrMo core was prepared by a facing-targets-type rf magnetron sputtering system. The core consisted of alternate CoZrMo and SiO2 layers. The coercive force was small and had a value of 2.8 A/m (0.035 Oe). The hysteresis loss at the maximum flux density of 0.1 T was 0.74 J/m3 and was 0.06 times the value of 12 J/m3 for the multilayered NiFeMo core. The iron loss of the multilayered CoZrMo core at 1 MHz and 0.1 T was 3.4 J/m3, which was 0.09 times the value of 38 J/m3 for the multilayered NiFeMo core. Magnetic domains were observed using a magneto-optical Kerr microscope. The shape and configuration of domains differed with frequency and place in the core. The process of magnetization is considered to be accomplished by nucleation of zigzag domains at the edge, followed by their growth and fusion and by rotation.