Patent ID: 8298689
Filing Date: 2012-10-30
Classification: G11B

Abstract:
1. A perpendicular magnetic recording medium comprising: a substrate, over a main surface of the substrate, a soft magnetic layer or layers; over the soft magnetic layer, a first orientation control layer with a hcp structure and, over the first orientation control layer, a second orientation control layer with an amorphous structure, over the second orientation control layer, an underlayer having a granular structure in which nonmagnetic crystal grains are grown in a columnar shape, and over the underlayer, a magnetic recording layer having a granular structure in which magnetic grains are grown in a columnar shape, wherein said first orientation control layer comprises Ti, said second orientation layer is formed between the first orientation control layer and the under layer and functions as a lattice spacing adjusting layer for blocking lattice spacing chains between the first orientation control layer and the underlayer, and said underlayer comprises one of CoCr or CoCrX (X is a nonmagnetic substance), CoCr-oxide, and CoCrX-oxide.