Magnetic recording medium for thermally assisted magnetic recording

A magnetic disk configured by a magnetic recording medium used for a thermally assisted magnetic recording system, said magnetic recording medium provided with:

• a substrate configured by glass,
• a heat radiation layer provided on said substrate,
• a heat retention layer provided on said heat radiation layer, and
• a recording layer provided on said heat retention layer via an intermediate layer;
• and
• said heat retention layer configured by a member having an effective refractive index lower than the effective refractive index of said recording layer and having a temperature diffusion coefficient determined by a specific heat, density, and heat conductivity rate higher than glass and lower than a metal.

A hard disk device provided with at least:

• at least one magnetic disk,
• a spindle motor which makes said magnetic recording medium rotate,
• a swing arm provided with a head which reads and write data from and to said magnetic recording medium at its front end,
• a voice coil motor which drives said swing arm, and
• a signal processing board;
• a magnetic recording medium configuring said magnetic disk provided with:
• a substrate configured by glass,
• a heat radiation layer provided on said substrate,
• a heat retention layer provided on said heat radiation layer, and
• a recording layer provided on said heat retention layer via an intermediate layer;
• and
• said heat retention layer configured by a member having an effective refractive index lower than the effective refractive index of said recording layer and having a temperature diffusion coefficient determined by a specific heat, density, and heat conductivity rate higher than glass and lower than a metal.