J. Phys. IV France 07 (1997) C1-495-C1-496
High Frequency Characteristics of Nanocrystalline Co-Fe-Hf-O Soft Magnetic FilmsY. Hayakawa, K. Ohminato, N. Hasegawa and A. Makino
Nagaoka Branch, Central Research Laboratory, Alps Electric Co., Ltd., 1-3-5 Higashi-Takami, Nagaoka 940, Japan
The microstructure, electrical resistivity, and high frequency soft magnetic properties of nanocrystalline Co-Fe-Hf-O films were investigated. The films were prepared by rf reactive sputtering technique in Ar + O2 mixed atmosphere under a static magnetic field or no field. In an as-deposited state, a Co44.3Fe19.1Hf14.5O22.1 film deposited in a static field consists of mixed structure of amorphous phase and bcc nanocrystals with 3 - 4 nm in diameter. The real part (ν) of complex permeability of 160 is almost constant up to 1GHz, and extremely high µ'/µ" of 61 at 100 MHz is obtained. These high frequency characteristics are caused by the high electrical resistivity (μ) of 13 µΩm and large anisotropy field (Hk) of 4.8 kA/m.
© EDP Sciences 1997