Patent ID: 6946191

Claim:
A magnetic recording medium comprising: a substrate; a magnetic layer formed on said substrate; a carbon-based protection layer comprising carbon and formed on said magnetic layer; and a lubrication layer formed on said carbon-based protection layer; said carbon-based protection layer comprising a rear boundary portion facing said magnetic layer and a front boundary portion facing said lubrication layer, said rear boundary portion comprising carbon and hydrogen, said front boundary portion including no hydrogen but comprising carbon and nitrogen; said carbon-based protection layer comprising a hydrogenated carbon protection layer facing said magnetic layer as said rear boundary portion and a nitrogenated carbon protection layer facing said lubrication layer as said front boundary portion, said hydrogenated carbon protection layer comprising carbon and hydrogen, said nitrogenated carbon protection layer including no hydrogen but comprising carbon and nitrogen, wherein said nitrogenated carbon protection layer is formed so that the concentration of nitrogen with respect to carbon falls within a range not smaller than 4 at % and not greater than 10 at %.