| 摘要 |
<p>Provided is a vertical magnetic recording medium (100) including a magnetic recording layer (122) which has a two-layer structure and in which the grain sizes of crystal grains are so designed as to improve SNR, while maintaining a high coercivity. According to a method for making the vertical magnetic recording medium (100), the vertical magnetic recording medium (100) comprises at least a groundwork layer (118), a first magnetic recording layer (122a) and a second magnetic recording layer (122b) formed on a disc substrate (110) in the named order. The first and second magnetic recording layers (122a, 122b) are ferromagnetic layers each having a granular structure in which grain boundary parts each comprising non-magnetic substance are formed between crystal grains grown in columnar shapes. Assuming that the average grain size of the crystal grains in the first magnetic recording layer (122a) is A nm and that the average grain size of the crystal grains in the second magnetic recording layer (122b) is B nm, A is smaller than B.</p> |
