MAGNETIC DISC SUBSTRATE AND MAGNETIC RECORDING MEDIUM THEREOF

摘要

The present invention relates to a magnetic disk substrate, in which an amplitude Wa of a waviness on a surface measured by using an interferometer for a versatile disk at a measuring wave-length of 5.0 mm is within the range of 0.1nm to 0.5 nm, an average amplitude Wb of a microwaviness generated on the waviness by using a microscopy for three-dimensional surface-structural analysis at a measuring wave-length of 30 µm to 200 µm is 0.3nm or less, and a value calculated by dividing the average amplitude Wb of the microwaviness by the amplitude Wa of the waviness is 0.6 or more.