Back to results
US 6,805,941 B1Granted
Magnetic recording medium
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorShigenori Hayashi
Life of this patent
Estimating the term…
Abstract
A magnetic recording medium having a diamond-like carbon (DLC) film added therein a Group IV element of the periodic table such as silicon, particularly in the vicinity of the boundary between the magnetic material and the formed DLC film. Since a DLC having low friction coefficient can be formed, the centerline average roughness can be reduced to 30 nm or even less. Accordingly, a magnetic recording medium improved in magnetic properties and in lubricity can be obtained.
Claims19
A hard disk device comprising:
- a magnetic head;
- a substrate;
- a magnetic film being provided on the substrate;
- a protective film being provided on the magnetic film and comprising diamond-like carbon,
- wherein the protective film includes at least a first element selected from the group consisting of silicon, germanium, tin and lead at a concentration of 20 atomic % or less,
- wherein a concentration of the first element at a first portion of the protective film is higher than a concentration of the element at a second portion of the protective film,
- wherein the first portion is closer to the substrate than the second portion,
- wherein the protective film comprises hydrogen at a concentration in a range of 10 to 60 atomic %,
- wherein a center line average roughness of the protective film is 30 nm or less,
- wherein the protective film includes at least a second element selected from Group III and Group V elements.
7 more elements
A hard disk device comprising:
- a magnetic head;
- a substrate;
- a magnetic film being provided on the substrate;
- a protective film being formed on the magnetic film and comprising diamond-like carbon,
- wherein the protective film includes at least a first element selected from the group consisting of silicon, germanium, tin and lead at a concentration of 20 atomic % or less,
- wherein a bottom surface of the protective film is in contact with the magnetic film,
- wherein a concentration of the first element increases gradually with increasing a depth from an upper surface of the protective film to a lower surface thereof,
- wherein the protective film comprises hydrogen at a concentration in a range of 10 to 60 atomic %,
- wherein a center line average roughness of the protective film is 30 nm or less,
- wherein the protective film includes at least a second element selected from Group III and Group V elements.
7 more elements
A hard disk device comprising:
- a magnetic head;
- a substrate;
- a magnetic film being provided on the substrate;
- a protective film being formed on the magnetic film and comprising diamond-like carbon,
- wherein the protective film includes at least a first layer and a second layer formed on the first layer,
- wherein the first layer includes at least a first element selected from the group consisting of silicon, germanium, tin and lead at a concentration of 20 atomic % or less while the second layer does not include the first element,
- wherein the protective film comprises hydrogen at a concentration in a range of 10 to 60 atomic %,
- wherein a center line average roughness of the protective film is 30 nm or less,
- wherein the protective film includes at least a second element selected from Group III and Group V elements.
6 more elements
A hard disk device comprising:
- a magnetic head;
- a substrate;
- a magnetic film being formed on the substrate;
- a protective film comprising diamond-like carbon and being formed on the magnetic film,
- wherein the protective film includes at least a first element selected from the group consisting of silicon, germanium, tin and lead at concentration of 20 atomic % or less,
- wherein a concentration of the first element at a first portion of the protective film is higher than a concentration of the first element at a second portion of the protective film,
- wherein the first portion is closer to the magnetic film than the second portion,
- wherein the protective film comprises hydrogen at a concentration in a range of 10 to 60 atomic %,
- wherein a center line average roughness of the protective film is 30 nm or less,
- wherein the protective film includes at least a second element selected from Group III and Group V elements,
- wherein Vicker's hardness of the protective film is 2000 kg/mm2 or more.
8 more elements
A hard disk device comprising:
- a magnetic head;
- a substrate;
- a magnetic film formed on the substrate;
- a protective film comprising diamond-like carbon and being formed on the magnetic film,
- wherein the protective film includes at least a first element selected from the group consisting of silicon, germanium, tin and lead at a concentration of 20 atomic % or less,
- wherein a bottom surface of the protective film is in contact with the magnetic film,
- wherein a concentration of the first element increases gradually with increasing a depth from an upper surface of the protective film to a lower surface thereof,
- wherein the protective film comprises hydrogen at a concentration in a range of 10 to 60 atomic %,
- wherein a center line average roughness of the protective film is 30 nm or less,
- wherein the protective film includes at least a second element selected from Group III and Group V elements,
- wherein Vicker's hardness of the protective film is 2000 kg/mm2 or more.
8 more elements
A hard disk device comprising:
- a magnetic head;
- a substrate;
- a magnetic film being formed on the substrate;
- a protective film comprising diamond-like carbon and being formed on the magnetic film,
- wherein the protective film includes at least a first layer and a second layer formed on the first layer,
- wherein the first layer includes at least a first element selected from the group consisting of silicon, germanium, tin at a concentration of 20 atomic % or less and lead while the second layer does not include the first element,
- wherein the protective film comprises hydrogen at a concentration in a range of 10 to 60 atomic %,
- wherein a center line average roughness of the protective film is 30 nm or less,
- wherein the protective film includes at least a second element selected from Group III and Group V elements,
- wherein Vicker's hardness of the protective film is 2000 kg/mm2 or more.
7 more elements
Dependencies are inferred from the claim text.