Perpendicular magnetic recording medium, manufacturing method thereof, and magnetic recording-reproducing apparatus

A magnetic recording-reproducing apparatus, comprising:

• the perpendicular magnetic recording medium comprising a nonmagnetic substrate, and a perpendicular magnetic layer containing at least one additive component selected from the group consisting of cobalt, platinum, molybdenum and tungsten, formed at 280 to 450° C. on the nonmagnetic substrate, and constructed to include a plurality of magnetic crystal grains separated from each other by crystal grain boundaries, the additive component being segregated in the crystal grain boundaries in the perpendicular magnetic layer;
• a mechanism for supporting and rotating the perpendicular magnetic recording medium;
• a magnetic head including an element for recording information in the perpendicular magnetic recording medium and another element for reproducing the recorded information;
• and
• a carriage assembly supporting the magnetic head such that the magnetic head is movable relative to the perpendicular magnetic recording medium.