Magnetic recording disk and magnetic recording and reproducing method

摘要

A magnetic recording disk favorably employable in a magnetic recording and reproducing method in which a magnetic recording disk is rotated at an increased rotation rate is essentially composed of a flexible support, a non-magnetic undercoating layer, and a thin magnetic layer which has a smooth surface and utilizes an iron-containing ferromagnetic metal powder, wherein the ferromagnetic metal powder contains an amount of an aluminum element in an amount of 5 to 30 atomic % based on the amount of iron element, and the magnetic layer is adjusted to have a squareness ratio of in the range of 0.15 to 0.30.