Patent ID: 6861126

Claim:
A magnetic recording medium comprising: a substrate; and a single magnetic layer containing mixture of cobalt (Co) and cobalt oxide (CoO) as a ferromagnetic metal, the magnetic recording medium is characterized in that the magnetic layer is divided into three regions, which are a first region, a second region and a third region respectively, wherein a thickness of each region in the direction normal to the plane of the substrate is equal, and with defining such that a maximum value of oxygen concentration in the first region is “Max 1 ”, a minimum value of oxygen concentration in the second region is “Min 2 ”, and a maximum value in the third region is “Max 3 ”, the values “Max 1 ”, “Min 2 ” and “Max 3 ” satisfy following equations: “Min 2 ”<“Max 1 ” and “Min 2 ”≦“Max 3 ”≦“Max 1 ”, and further characterized in that oxygen concentration prescribed by O/(Co+CoO) and oxygen concentration of Min 2 is more than 18% and less than 33% respectively.