PRODUCTION OF MAGNETIC DISK

PURPOSE:To prevent the exfoliation of a coating film provided to a magnetic recording medium by subjecting and inorg. oxide film to a heat treatment under the reduce pressure below the atmospheric pressure in the stage of coating the inorg. oxide film on the magnetic recording medium provided on a substrate. CONSTITUTION:A sputtered gamma-Fe2O3 film 2 is formed on the disk-shaped aluminum alloy substrate 1 and thereafter an ethyl alcohol soln. of about 10% tetrahydroxysilane is coated thereon by a spin coating method. Such film is subjected to the heat treatment in a vacuum furnace and a lubricating layer 4 is provided on the SiO2 film 5. The inorg. oxide film is subjected to the heat treatment under the reduced pressure below the atmospheric pressure in the stage of coating the inorg. oxide film on the magnetic recording medium; therefore, the dehydration condensation reaction is accelerated and the film is changed to the film having excellent hardness and strength by the low-temp. heat treatment. Such film plays the role of providing lubricative protection to the medium and is also the secure underlying layer in the case of producing a lubricating layer so as to provide the higher adhesive power to the lubricating layer. The attraction of a magnetic head is thereby prevented. The exfoliation of the lubricating film is prevented in the case of using the lubricating film and the exfoliation of the coating film provided on the magnetic recording medium is prevented as well.