| 摘要 |
A METHOD FOR MANUFACTURING A SUBSTRATE FOR A MAGNETIC DISK, INCLUDING THE STEPS OF (A) POLISHING A SUBSTRATE WITH A POLISHING COMPOSITION A CONTAINING ALUMINA ABRASIVES HAVING AN AVERAGE PARTICLE SIZE OF FROM 0.05 TO 0.5 UM, AND AN OXIDIZING AGENT, AND (B) POLISHING THE SUBSTRATE WITH A POLISHING COMPOSITION B CONTAINING SILICA PARTICLES HAVING AN AVERAGE PARTICLE SIZE OF FROM 0.005 TO 0.1 UM; A SUBSTRATE FOR A MAGNETIC DISK, OBTAINABLE BY THE METHOD FOR MANUFACTURING A SUBSTRATE FOR A MAGNETIC DISK; AND A SUBSTRATE FOR A MAGNETIC DISK HAVING THE FOLLOWING SURFACE PROPERTIES OF A LONG-WAVELENGTH WAVINESS OF 0.05 NM OR MORE AND 0.3 NM OR LESS, AND AN AFM SURFACE ROUGHNESS OF 0.03 NM OR MORE AND 0.2 NM OR LESS. THE SUBSTRATE FOR A MAGNETIC DISK MAY BE SUITABLY USED IN THE MANUFACTURE OF A HARD DISK HAVING A HIGH RECORDING DENSITY. ESPECIALLY, A HARD DISK HAVING A RECORDING DENSITY OF 50 G BITS OR MORE PER SQUARE INCH MAY BE INDUSTRIALLY MANUFACTURED. |
