Wear-resistance and signal-to-noise ratio in γ-Fe2O3thin film disks

Wear-resistance in an Al2O3pin-disk wear-test and SNR for γ-Fe2O3thin film disk composites (γ-Fe2O3thin film/substrate) were investigated. It was found that wear-resistance enhancement for the films is essentially accompanied by SNR deterioration due to crystallite growth. On the other hand, an increased Knoop hardness, HK, for the substrate surface greatly enhanced wear-resistance. Use of heat-resistant, defect-free CrO3anodization substrates, which have 420 kg/mm²HK, successfully minimized the wear-depth. Finally, it was found that the γ-Fe2O3thin film disks with a high-SNR can have higher wear-resistance than metallic thin film disks, because the oxide films themselves have high hardness.