Tribological studies of chromium oxide films for magnetic recording applications

Hard coatings are commonly used in magnetic heads and media for protection against corrosion and wear. Chromium oxide coatings have been developed for protection of the tape bearing surface of digital compact cassette (DCC) heads. Based on initial screening tests and lifetime tests, a 50-nm thick rf-sputtered chromium oxide coating exhibits best durability. Surface analytical techniques used for structural and chemical characterization show that chrome oxide coating is polycrystalline and with stoichiometry close to Cr2O3. Micromechanical characterization was carried out using a nanoindenter to measure hardness, Young's modulus and scratch resistance. The coatings exhibited hardness as high as 30 GPa combined with a good scratch resistance. A pin-on-disk tester was used to measure friction and wear performance. Since these coatings are hard, scratch and wear resistant (with a low coefficient of friction), they should find many other industrial applications such as magnetic rigid disks and magnetic disk heads. (C) 1997 Elsevier Science S.A.