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 (μ′) 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 (ρ) of 13 μ Ω and large anisotropy field (Hk) of 4.8 kA/m.
ASJC Scopus subject areas
- Physics and Astronomy(all)