Orientation of Nano-Grains in Hard-Disk Media on Ion-Beam Textured Substrates

The preferred crystal orientations in nano-grains of multilayered magnetic recording media were studied in detail with X-ray diffraction. No in-plane orientation was observed in the media on a flat substrate, while grooved substrates made by ion-beam etching have a modulation of the line width with two-fold symmetry, suggesting that the crystal planes are modulated by the groove slopes. Dislocations to accommodate mismatch between hcp-Co alloy grains sitting on adjacent slopes of grooves might induce the preferred crystalline orientation