| abstract |
(57) [Summary] [PROBLEMS] To improve the polishing rate, to reduce surface defects such as scratches and pits, and to improve surface roughness (Ra) and undulation. (Wa) a polishing composition capable of improving the surface smoothness such as, a polishing method using the polishing composition, a surface roughness (R a) and a magnetic disk substrate having improved surface smoothness such as waviness (Wa); and a method of manufacturing the same. [1] A polishing composition comprising silica particles, water and an Fe salt and / or an Al salt of polyaminocarboxylic acid, [2] the polishing composition according to [1], further comprising an inorganic acid and / or an organic acid. Production of a magnetic disk substrate having a polishing composition, a polishing method using the polishing composition according to [1] or [2], and a polishing step using the polishing composition according to [1] or [2]. A method and a magnetic disk substrate manufactured by using the polishing composition according to [1] or [2]. |