COMPOSITION FOR TEXTURING OF MAGNETIC DISK

PURPOSE:To decrease recording errors and to increase recording density by using a grinding liquid dispersed with abrasive grains consisting of sintered compacts of polycrystalline alumina produced by a sol-gel method. CONSTITUTION:A magnetic disk 1 subjected to texturing is constituted by forming a substrate 12 on a substrate 11 at 5 to 20mum thickness by Ni-P plating, etc., then subjecting the surface to mirror polishing to 5 to 20mum surface roughness (Rmax). While the disk 1 is kept rotated, the surface of the substrate 12 is subjected to texturing by applying the grinding liquid 5 on a pad 2 for sliding formed of flexible fibers, such as nylon, by which line traces are formed. A magnetic layer 13 is then formed as thinly as 0.05 to 0.15mum on the substrate 12 by vapor deposition, etc., and further, carbon or the like is formed as a thin protective layer 14 of 0.01 to 0.03mum by a sputtering method. Since the magnetic layer 13 and the protective layer 14 are thin, nearly the same line traces as the line traces of the texturing appear on the surface. The polycrystalline alumina gels which are produced by the sol-gel method and are pulverized to