A method of producing a NiP alloy sputtering target, wherein a NiP alloy having a P content of 15 to 21 wt % and remainder being Ni and unavoidable impurities is melted and atomized to prepare a NiP alloy atomized powder having an average grain size of 100 m or less, the NiP alloy atomized powder is mixed with a pure Ni atomized powder, and the obtained mixed powder is hot pressed. An object of the present invention is to provide a method of producing a NiP alloy sputtering target which achieves a small deviation from an intended composition.

A graphite plate has a surface roughness Ra from 10 m to less than 40 m and a surface-unevenness variation of 0.01% to 0.135% in any span 80 mm long within the surface of the graphite plate. A method for producing a graphite plate, includes r subjecting a polymer film to a heat treatment in an inert gas, wherein the heat treatment is conducted at 2400 C. to 3200 C., and a pressure of 10 kg/cm2 to 100 kg/cm.sup.2 is applied to the polymer film at 200 C. or higher.

A perpendicular magnetic recording medium adapted for high recording density and high data recording rate comprises a non-magnetic substrate having at least one surface with a layer stack formed thereon, the layer stack including a perpendicular recording layer containing a plurality of columnar-shaped magnetic grains extending perpendicularly to the substrate surface for a length, with a first end distal the surface and a second end proximal the surface, wherein each of the magnetic grains has: (1) a gradient of perpendicular magnetic coercivity H.sub.k extending along its length between the first end and second ends; and (2) predetermined local exchange coupling strengths along the length.

A magnetic recording medium 11 in which the outermost surface of a protective layer 3 on a lubricant layer 4 side contains carbon and nitrogen of 10 atomic % to 90 atomic %, the lubricant layer 4 is formed by being in contact with the outermost surface, and contains a compound A of Formula (1) and a compound B of Formula (2), a mass ratio (A/B) of the compound A with respect to the compound B is 0.2 to 0.3, the average molecular weights of the compounds A and B are 1,500 to 2,000 and 1,300 to 2,400, respectively, and the average film thickness is 0.5 nm to 2 nm.

R1-C.sub.6H.sub.4OCH.sub.2CH(OH)CH.sub.2OCH.sub.2R2-CH.sub.2OCH.sub.2CH(OH)CH.sub.2OH (1) (R1 is an alkoxy group having 1 to 4 carbon atoms. R2 is CF.sub.2O(CF.sub.2CF.sub.2O)x(CF.sub.2O)yCF.sub.2.)

HOCH.sub.2CF.sub.2CF.sub.2O(CF.sub.2CF.sub.2CF.sub.2O)mCF.sub.2CF.sub.2CH.sub.2OCH.sub.2CH(OH)CH.sub.2OH (2)

There is provided a magnetic recording medium including a surface having a longitudinal direction and a lateral direction. An arithmetic average roughness Ra, a ratio PSD.sub.MD,short/PSD.sub.TD,short, and a ratio PSD.sub.MD,long/PSD.sub.TD,long on the surface satisfy Ra3.0 nm, PSD.sub.MD,short/PSD.sub.TD,short0.65, and 1.3PSD.sub.MD,long/PSD.sub.TD,long2.3, in which PSD.sub.MD,short is an average value of PSD values in a range from 0.15 m to 0.4 m in the longitudinal direction of the surface, PSD.sub.TD,short is an average value of PSD values in a range from 0.15 m to 0.4 m in the lateral direction of the surface, PSD.sub.MD,long is an average value of PSD values in a range from 0.4 m to 5.0 m in the longitudinal direction of the surface, and PSD.sub.TD,long is an average value of PSD values in a range from 0.4 m to 5.0 m in the lateral direction of the surface.