Patent ID: 6844724

Claim:
A method of measuring the magnetic moment (M r t) and anisotropy field strength (H k ) of a perpendicular magnetic recording medium comprising a magnetically soft underlayer (SUL), comprising sequential steps of: (a) providing a perpendicular magnetic recording medium comprising a magnetically soft underlayer (SUL) and a planar-surfaced perpendicular magnetic recording layer; (b) determining a compensated magnetic moment (M r t) comp of said recording layer for a given strength (H) of a generally in-plane magnetic field applied generally parallel to said planar surface of said recording layer; (c) repeating step (b) for a plurality of different strengths of said in-plane applied magnetic fields (H) for determining the variation of the compensated magnetic moments (M r t) comp of said recording layer as a function of the strengths (H) of said generally in-plane applied magnetic fields; and (d) determining the remanent magnetic moment (M r t(0)) at zero (0) field strength (H) and the anisotropy field strength (H k ) from the measured variation of the compensated magnetic moments (M r t) comp of said recording layer as a function of the strength (H) of said generally in-plane applied magnetic fields.