Compensation technique for measurement of magnetic moment and anisotropy field of perpendicular recording media with soft underlayer

摘要

A method of measuring the magnetic moment (M_rt) and anisotropy field strength (H_k) of a perpendicular magnetic recording medium comprising a planar-surfaced perpendicular recording layer and a magnetically soft underlayer (SUL) is provided. A compensated magnetic moment (M_rt)_comp of the recording layer is determined for a given strength (H) of a generally in-plane magnetic field applied generally to the recording layer. The compensated magnetic moment (M_rt)_comp of the recording layer is determined for a plurality of different in-plane applied magnetic field (H) strengths to determine the variation of the compensated magnetic moment (M_rt)_comp of the recording layer as a function of the strength (H) of the generally in-plane applied magnetic fields. The remanent magnetic moment (M_rt(0)) at zero (0) field strength (H) and the anisotropy field strength (H_k) is determined from the measured variation of the compensated magnetic moment (M_rt)_comp of the recording layer as a function of the strength (H) of the generally in-plane applied magnetic fields.