SUBSTRATE FOR PERPENDICULAR MAGNETIC RECORDING MEDIUM, AND PERPENDICULAR MAGNETIC RECORDING MEDIUM USING THE SAME

PROBLEM TO BE SOLVED: To provide a substrate for a perpendicular magnetic recording medium capable of achieving excellent reproducing signal quality and its stabilization of the magnetic recording medium irrespective of a final working method of the substrate, and to provide the perpendicular magnetic recording medium using the substrate. SOLUTION: In the substrate for the magnetic recording medium having a doughnut shape and provided with a principal surface, an inner peripheral surface extended on the inner side of the principal surface and an outer peripheral surface extended on the outer side of the principal surface, when the shape of the principal surface is defined as a function Z(x, y) of coordinates x-y, a root-mean-square inclination angle (θsΔq) defined as an arc tangent function (tan-1(sΔq)) of a root-mean-square inclination (sΔq) to be a root-mean-square to the entire principal surface of surface inclinations (Δρ) of fine regions of the principal surface represented by a formula is specified to be ≤5°. COPYRIGHT: (C)2009,JPO&INPIT