Abstract: A magnetic thin film comprised of at least one, usually two magnetic metals selected from iron, nickel, and cobalt is vapor phase grown on a substrate, for example, polyimide film by introducing chemical compounds of the metals in vapor form, a reducing gas, and optionally, an oxidizing gas, into a vacuum chamber where the substrate is placed and preferably heated to a temperature of at least 100.degree. C., and subjecting the reaction gases to plasma excitation, thereby achieving the vapor phase growth of the magnetic thin film on the substrate.

Abstract: A magnetic recording medium is coated, over its magnetic layer, with a thin film of a siloxane-linkage-containing polymer. The magnetic layer consists of a thin film formed by vacuum evaporation or sputtering or by dispersion of a ferromagnetic metal powder in a binder. The polymer having the siloxane linkage is prepared by polymerizing an organo-silicon compound which either inherently possesses the linkage or is capable of producing it. The polymerization is preferably effected by the plasma polymerization technique.

Abstract: In a magnetic recording medium comprising a plastic base film and a magnetic layer formed thereon, the base film is plasma treated at frequencies in the range of 10 kHz to 200 kHz in an inorganic gas such as argon and nitrogen and preferably, in an inorganic gas containing at least 5% of oxygen.

Abstract: A magnetic recording medium comprises a base, a thin ferromagnetic metal film, and a plasma-polymerized organic material layer sandwiched between them. The plasma-polymer is made of an organic metal and the layer is not less than 10 .ANG. thick. The ferromagnetic metal film is composed mainly of a cobalt-nickel alloy and formed by vacuum deposition.