Patent ID: 6716542
Filing Date: 2004-04-06
Classification: C22C,C23C,G11B,Y10T

Abstract:
A magnetic recording medium comprising at least a nonmagnetic undercoat layer, a magnetic layer, and a protective layer laminated sequentially on a nonmagnetic substrate, whereinthe magnetic layer is a granular magnetic layer having a structure in which crystal grains containing Co and having ferromagnetism are surrounded with oxide grain boundaries, the magnetic layer has been obtained by RF sputtering of a sputtering target for a magnetic recording medium, the sputtering target comprising a mixture of metal and an oxide, the oxide having a particle diameter of 5 &mgr;m or less, and defects attributed to particles of the oxide and measuring 0.05 &mgr;m or more are not present on a surface of the magnetic recording medium.