MAGNETIC DISK

PURPOSE:To improve wear resistance and to prevent attraction by providing island-shaped projections which are formed of one kind among metals, silicon and boron and are cured by oxidizing or nitriding on a flat magnetic recording medium or a protective film formed on this magnetic recording medium. CONSTITUTION:The film of the magnetic recording medium 3 consisting of Co-Ni is formed to 600Angstrom on a commercially marketed substrate constituted by forming an underlying cured film 2 of an Ni-P plating film on the surface of an Al-Mg alloy substrate 1 and subjecting the surface to mirror finishing and an SiO2 film 4 which is a protective film is formed to 500Angstrom thereon. The island-shaped projections 5 of Al are provided on this SiO2 protective film 4 and further, this disk is heat-treated in an oxygen atmosphere, by which the Al is oxidized and cured to form the island-shaped projections 5 of Al2O3. The island-shaped projections 5 formed in such a manner decrease the true contact area with a magnetic head slider. The attraction force and friction force between a magnetic disk and the magnetic head slider are thereby decreased. Since the projections 5 are subjected to the curing treatment, the wear resistance is improved as well.