Production of magnetic recording media
AssigneeBASF SE
InventorsArend Werner, Hartmut Hibst, Erich Haedicke, Johann Kronenbitter
Life of this patent
Estimating the term…
Abstract
Magnetic recording media essentially consisting of a disk-shaped aluminum substrate, a nonmagnetic (Ni-P) lower film, a chromium-containing intermediate film and a ferromagnetic metal film are produced by a process in which the surface of the (Ni-P) lower film is cleaned by RF sputter etching and then oxidized.
Claims9
A process for the production of a magnetic recording medium consisting essentially of a disk-shaped aluminum substrate bearing a lower non-magnetic (Ni-P) film, a chromium film and an upper ferromagnetic metal film, which comprises:
- (1) removing material from the surface of the (Ni-P) film, by RF sputter etching to a depth of from 1 to 20 nm,
- (2) oxidizing the etched (Ni-P) surface with an oxygen-containing gas for from 10 seconds to 12 hours, and
- (3) thereafter depositing the chromium film and the ferromagnetic metal film in succession on the (Ni-P) film.
A process for the production of a magnetic recording medium consisting essentially of a disk-shaped aluminum substrate bearing a lower non-magnetic (Ni-P) film, a chromium film and an upper ferromagnetic metal film, which comprises:
- (1) RF sputter etching the surface of the (Ni-P) film in a miture of argon and oxygen as sputter gas, and
- (2) thereafter depositing the chromium film and the ferromagnetic metal film in succession on the (Ni-P) film.
A process for the production of a magnetic rcording medium consisting essentially of a disk-shaped aluminum substrate bearing a lower nonmagnetic (Ni-P) film, a chromium film and an upper ferromagnetic metal film, which comprises:
- (1) removing material from the surface of the (Ni-P) film,
- (2) applying an intermediate oxygen-containing chromium film to the (Ni-P) film by reactive sputtering of chromium in a mixture of argon and oxygen as sputter gas, and
- (3) thereafter depositing the chromium film and the ferromagnetic metal film in succession on the (Ni-P) film.
Dependencies are inferred from the claim text.