Magnetic disk and method of producing the same
View Patent ↗A magnetic disk includes a substrate on which a nonmagnetic metal layer, a magnetic layer, a carbon-based protection layer, an alcohol-based coupling layer, and a lubrication layer successively formed thereon. The lubrication layer contains a hydroxyl- or a carboxyl-modified compound as a lubricating material. The alcohol-based coupling layer contains, for example, lower alcohol as a main component and is deposited on the carbon-based protection layer, for example, by vapor deposition. The alcohol-based coupling layer may be replaced by a layer containing lower alcohol. The carbon-based protection layer may be deposited by plasma CVD.
1. A magnetic disk adapted to be loaded in a magnetic disk apparatus of a load unload system, comprising:
a disk substrate;
a magnetic layer formed over the disk substrate;
a carbon-based protection layer formed on the magnetic layer;
an alcohol-based coupling layer containing only alcohol and formed on a carbon-based protection layer, an alcohol-based coupling layer having a first hydroxyl group; and
a lubrication layer formed on the an alcohol-based coupling layer, the lubrication layer containing a hydroxyl-modified perfluoropolyether compound having a second hydroxyl group at a terminal end;
wherein hydrogen bond is formed between the second hydroxyl group of the lubrication layer and the first hydroxyl group of the alcohol-based coupling layer to produce coupling force by the hydrogen bond between the carbon-based protection layer and the lubrication layer,
wherein a bonded ratio of the lubrication layer for the carbon-based protection layer is not smaller than 70% by interposing the alcohol-based coupling layer between the carbon-based protection layer and the lubrication layer.
2. A magnetic disk according to claim 1 , wherein the alcohol-based coupling layer or the alcohol contains lower alcohol as a main component.
3. A magnetic disk according to claim 1 , wherein the carbon-based protection layer contains hydrogen or nitrogen.
4. A magnetic disk according to claim 1 , wherein the thickness of the alcohol-based coupling layer is determined upon deposition.
5. A magnetic disk according to claim 1 , wherein the alcohol-based coupling layer has a thickness within a range between 0.5-2.0 angstroms and is formed by vapor deposition.