Abstract: In a magnetic recording medium comprising a length of a non-magnetic plastic substrate and a magnetic thin layer of Co or Co-Ni or Co-Ni-Cr formed thereon, when the coercive force of the medium is measured by changing the measuring direction in a plane defined by a longitudinal direction of the substrate and a direction normal to the major surface of the substrate, the following relationship is met:(Hc.sub.max -Hc.sub.min)/Hc(0).ltoreq.0.9where Hc.sub.max is the maximum coercive force, Hc.sub.min is the minimum coercive force, and Hc(0) is a coercive force in the longitudinal direction of the substrate.

Abstract: In a magnetic recording medium comprising a non-magnetic substrate and a magnetic layer of Co or Co-Ni in the form of a continuous thin film on the substrate, the magnetic layer has oxygen-rich sub-layers at its surfaces adjacent to and remote from the substrate. The oxygen-rich sub-layers are produced by injecting energy particles containing oxygen to the surface of the substrate during the initial and final stages of formation of the magnetic layer.

Abstract: A magnetic recording medium which comprises a magnetic layer formed on a substrate and comprising Co, or Co and one to three elements selected from the group consisting of Ni, Cr and O, wherein, when the magnetic layer is divided equally into four portions in the direction of the thickness of the magnetic layer, the density of the portion located farthest from the substrate is greater by at least 20% than the average density of three other portions.

Abstract: A magnetic recording medium which comprises a first layer formed on a substrate and comprising Co; Co and Ni; Co and O; or Co, Ni and O, and a second magnetic layer formed on the first magnetic layer and comprising Co and Cr at a weight ratio of Co/Cr being from 2.5 to 8.

Abstract: A magnetic recording medium which comprises a magnetic layer formed on a substrate and comprising Co, or Co and one to three elements selected from the group consisting of Ni, Cr and O, said magnetic layer comprising sequentially from the substrate side, a first portion composed of crystal particles which are not inclined relative to the normal line of the principal plane of the substrate, a second portion composed of columnar crystal particles which are inclined relative to the normal line of the principal plane of the substrate, and a third portion composed of crystal particles which are not inclined relative to the normal line of the principal plane of the substrate.

Abstract: A process for producing a magnetic recording medium which comprises forming on a non-magnetic substrate a magnetic thin layer composed of columnar crystal particles comprising Co, or Co and Ni and/or Cr by vapor/depositing the metal atoms at an angle of incidence of at least 20.degree. relative to the normal line of the principal plane of the substrate, and then forcibly oxidizing the magnetic thin layer by electrochemical treatment to form an oxide layer on the surface of the columnar crystal particles of the magnetic thin layer, and thereby to form a magnetic layer.

Abstract: A magnetic recording medium having a ferromagnetic layer formed by oblique vapor deposition wherein the residual magnetic flux density in the width direction of the recording medium is larger than the residual magnetic flux density in the longitudinal direction shows the SN ratio in a practical level at recording in the width direction.