PURPOSE: To obtain the titled disk having excellent durability and especialy suitable for high-density recording by forming a magnetic layer on a disk wherein a minute protrusion having height less than the necessary spacing and composed of a substance having more than a specified hardness and m.p. and which does not react chemically with the base disk material is provided.
CONSTITUTION: Base disk materials for a magnetic disk, e.g., Al powder and a substance which does not react chemically with the material such as carborundum particles 31 having ≥7 hardness, ≥800°C m.p., 0.3W2μ particle diameter, and ≥0.2calorie/cm.sec.°C heat conductivity are melted and mixed, then rolled, molded, cut, and polished to form a base disk having thickness less than that of the necessary spacing. The disk is etched, and a minute protrusion wherein the particle 31 has the height less than the necessary spacing is provided on the etched base disk 27. A magnetic layer 12 is formed in ≤0.2μ thickness on the disk thus manufactured by coating or sputtering. The particle 31 is protruded from the surface of the magnetic layer 12, and the magnetic layer 12 is kept out of direct contact with a magnetic head. Consequently, a disk 73 having a long service life is obtained.
ABE KATSUO
IMAMURA MASAAKI
NAGAIKE SADAKUNI
