JPS6459627A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve the productivity of a magnetic recording medium by providing a thin Cr underlying layer which consists of the columnar particles of Cr having a body centered cubic crystal structure or alloy essentially consisting of said Cr and the side faces of which are isolated by oxide layers or nitride layers on a nonmagnetic substrate. CONSTITUTION:A substrate 9 formed with an Ni-P alloy plating layer 2 is formed on the Al substrate 1 and the Cr underlying layer consisting of the Cr having the body centered cubic crystal structure or the alloy essentially consisting of the Cr is formed on such substrate. The Cr underlying layer 3 is subjected to a pressurization treatment in an atmosphere of oxidative gas or nitridable gas or the gaseous mixture composed thereof to form the oxide layer or the nitride layer or the mixed layers thereof on the surfaces and grain boundaries of the columnar particles of the underlying layer 3. The oxide layers or nitride layers formed on the surfaces of the columnar particles are removed by a sputter etching treatment in the inert atmosphere and thereafter, a magnetic Co-Ni layer 6 which is a thin ferromagnetic metallic film is formed on the underlying layer 3.