Studies of the magnetic and reversal properties for thin CoCrTa films

The effects of magnetic layer thickness on film structural and magnetic properties were studied systematically with emphasis on the thermal effects on thin recording media films. X-ray diffraction measurements reveal structural changes as thickness decreases, and the existence of a "Cr enriched phase" associated with the interface. The saturation magnetization M_s decreases with thickness and the thickness of the "dead layer" was found to be ∼ 23 Å. Systematic measurements of effective anisotropy, coercivity and saturation magnetization as functions of temperature have been carried out. Magnetic viscosity measurements reveal that thermal stability is affected not only by grain sizes but also by anisotropy reduction associated with nanostructure evolution, as the film thickness decreases.