| 摘要 |
Embodiments of the present invention help to improve corrosion resistance and durability by providing a functional diamond like carbon (DLC) protective layer for a perpendicular magnetic recording medium using a granular magnetic layer. According to one embodiment, when a DLC protective layer that protects a granular magnetic layer of a perpendicular magnetic recording medium is formed using a CVD method, the thickness of a first layer on the granular magnetic layer is set to 7.5 to 25% of the total thickness of the protective layer and a hydrogen content of the first layer is set to 33 to 38%, the thickness of a second layer is set to 50 to 85% of the total thickness of the protective layer and a nitrogen content of the second layer is set to 3 to 7%, and the thickness of a third layer located at the outermost side of the protective layer is set to 7.5 to 25% of the total thickness of the protective layer and a hydrogen content of the third layer is set to 25% or less.
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