Magnetic recording medium and process for producing the same

A magnetic recording medium comprising a substrate, a ferromagnetic thin film formed on substrate, a protective film formed directly on the ferromagnetic thin film, and a lubricant layer made of an organic material on said protective film, said ferromagnetic thin film and said protective film being formed continuously without exposing said ferromagnetic thin film and said protective film to air and while maintaining said ferromagnetic thin film and said protective film in a vacuum, said protective film having two layers, the first layer being made of the element Si, Ge or B, a compound of Si, Ge or B, or an alloy principally made of Si, Ge, or B and the second layer being made of the element Sn, Pb, In, Se, Te, Cu, Ag or Au, a Sn-based alloy, a Pb-based alloy, an In-based alloy, a Se-based alloy, a Te-based alloy, a Cu-based alloy, an Ag-based alloy or an Au-based alloy.

A magnetic recording medium comprising a substrate, a ferromagnetic thin film formed on the substrate, and a protective film formed on the ferromagnetic thin film, an interface of said ferromagnetic thin film and said protective film being free of a reaction deposit of elements constituting said ferromagnetic thin film, exclusive of reaction deposit of elements constituting said protective film, and contamination by foreign substances, said ferromagnetic thin film being made of a material selected from the group consisting of Co-based alloys, Fe-based alloys and Ni-based alloys and said protective film being made of the element Si, the element Ge, the element B, an alloy principally made of Si, or Ge, or a B compound selected from the group consisting of B.sub.4 Si, B.sub.6 Si, and a mixture of B.sub.4 C and B.sub.4 Si.

A magnetic recording medium comprising a substrate, a ferromagnetic thin film made of a Co-based alloy, a Fe-based alloy or a Ni-based alloy formed on the substrate, and a protective film formed on the ferromagnetic thin film, an interface of said ferromagnetic thin film and said protective film being free of a reaction deposit of elements constituting said ferromagnetic thin film, exclusive of reaction deposit of elements constituting said protective film, and contamination by foreign substances, wherein said protective film comprises two layers, a first layer of which is made of Si, Ge or B, a compound of Si, Ge or B, or an alloy principally made of Si, Ge, or B and a second layer which is made of Sn, Pb, In, Se, Te, Cu, Ag or Au, or a Sn-based alloy, a Pb-based alloy, an In-based alloy, a Se-based alloy, a Te-based alloy, a Cu-based alloy, an Ag-based alloy or an Au-based alloy.

A magnetic recording medium produced by a process comprising forming a ferromagnetic thin film on a substrate while maintaining said substrate under a vacuum atmosphere, and forming a protective film on said ferromagnetic thin film while maintaining said substrate and ferromagnetic thin film under said vacuum atmosphere, said protective film being formed directly on said ferromagnetic thin film and the interface of said ferromagnetic thin film and said protective film being free from contamination, wherein said protective film is made of a material selected from the group consisting of the element Si, the element Ge, the element B, an alloy principally made of Si, or Ge, B.sub.4 Si, B.sub.6 Si and a mixture of B.sub.4 C and B.sub.4 Si.

A magnetic recording medium produced by a process comprising forming a ferromagnetic thin film on a substrate while maintaining said substrate under a vacuum atmosphere, and forming a protective film on said ferromagnetic thin film while maintaining said substrate and ferromagnetic thin film under said vacuum atmosphere, said protective film being formed directly on said ferromagnetic thin film and the interface of said ferromagnetic thin film and said protective film being free from contamination, wherein said protective film comprises two layers, a first layer of which is made of Si, Ge or B, a compound

A magnetic recording medium comprising a substrate, a ferromagnetic thin film formed on the substrate, and a protective film formed on the ferromagnetic thin film, an interface of said ferromagnetic thin film and said protective film being free of a reaction deposit of elements constituting said ferromagnetic thin film, exclusive of reaction deposit of elements constituting said protective film, and contamination by foreign substances, said ferromagnetic thin film being made of a material selected from the group consisting of Co-based alloys, Fe-based alloys and Ni-based alloys and said protective film being made of B.sub.4 Si.

A magnetic recording medium comprising a substrate, a ferromagnetic thin film formed on the substrate, and a protective film formed on the ferromagnetic thin film, an interface of said ferromagnetic thin film and said protective film being free of a reaction deposit of elements constituting said ferromagnetic thin film, exclusive of reaction deposit of elements constituting said protective film, and contamination by foreign substances, said ferromagnetic thin film being made of a material selected from the group consisting of Co-based alloys, Fe-based alloys and Ni-based alloys and said protective film being made of B.sub.6 Si.

A magnetic recording medium comprising a substrate, a ferromagnetic thin film formed on the substrate and a protective film formed on the ferromagnetic thin film, an interface of said ferromagnetic thin film and said protective film being free of a reaction deposit of elements constituting said ferromagnetic thin film exclusive of reaction deposit of elements constituting said protective film, and contamination by foreign substances, said ferromagnetic thin film being made of a material selected from the group consisting of Co-based alloys, Fe-based alloys and Ni-based alloys and said protective film being made of the element B.

A magnetic recording medium comprising a substrate, a ferromagnetic thin film formed on the substrate, and a protective film formed on the ferromagnetic thin film, an interface of said ferromagnetic thin film and said protective film being free of a reaction deposit of elements constituting said ferromagnetic thin film, exclusive of reaction deposit of elements constituting said protective film, and contamination by foreign substances, said ferromagnetic thin film being made of a material selected from the group consisting of Co-based alloys, Fe-based alloys and Ni-based alloys and said protective film being made of an alloy of Si and B or an alloy of Ge and B.