MICROSTRUCTURE AND TEXTURE EVOLUTION OF CR THIN-FILMS WITH THICKNESS

Microstructure and texture of Cr thin films sputter deposited on NiP-coated AlMg substrates were studied using transmission electron microscopy (TEM). The sample tilt method in TEM has proven to be very effective in determining the fiber axis of weakly textured films. It was found that both the grain size and texture of the Cr films are strongly dependent on their thickness and deposition conditions. For Cr films deposited on 300-degrees-C preheated substrates, the grain size increases monotonically with the film thickness. The texture changes from no texture (approximately 100 angstrom) to a [001] fiber texture (200-2000 angstrom), and then to a [011] fiber texture (approximately 5000 angstrom). A 2000-angstrom-thick film deposited on a room-temperature substrate shows a strong [011] texture and a smaller grain size than that of a film with the same thickness but deposited on a preheated substrate. Correlations between the in-plane coercivity of Co-based alloy thin films for longitudinal magnetic recording and the grain size and texture of Cr underlayers are also discussed.