JP2001160214A5 - - Google Patents

Claims (11)

  In a magnetic recording medium in which a magnetic alloy layer containing Co as a main component, a protective layer, and a lubricating layer are formed in this order on a substrate via a base layer, the base layer is formed of a substantially amorphous layer. A load ratio in a load curve composed of a plurality of underlayers including a structure in which a second underlayer consisting of an underlayer and a crystalline layer is laminated in this order, and obtained from the surface roughness curve of the magnetic recording medium ΔBH [0.01, 50] (= | BH [0.01%]-BH [50%] | between the height BH [0.01%] where the load becomes 0.01% and the height BH [50%] where the load ratio becomes 50% ) Is 3 nm or more and 6 nm or less. In the load curve obtained from the surface roughness curve of the magnetic recording medium, the difference ΔBH [0.01,0.8] between the height BH [0.01%] at which the load ratio is 0.01% and the height BH [0.8%] at which the load ratio is 0.8% The magnetic recording medium according to claim 1, wherein (= | BH [0.01%] − BH [0.8%] |) is 0.2 nm or more and 3 nm or less. The first underlayer is made of a substantially amorphous alloy mainly composed of Co or Ni, and the second underlayer is made of Cr or an alloy mainly composed of Cr. The magnetic recording medium according to claim 1 or 2. 4. The thickness of the first underlayer is not less than 20 nm and not more than 80 nm, and the thickness of the second underlayer is not less than 3 nm and not more than 60 nm. Magnetic recording media. In a magnetic recording medium in which a magnetic alloy layer mainly composed of Co and a protective layer and a lubricating layer are formed on a substrate via an underlayer, the underlayer is a crystalline layer having a thickness of 3 nm to 50 nm. In the load curve obtained from the surface roughness curve of the magnetic recording medium, the height BH [0.01%] where the load ratio is 0.01% and the height BH [50%] where the load ratio is 50% A magnetic recording medium having a difference ΔBH [0.01, 50] (= | BH [0.01%] − BH [50%] |) of 3 nm or more and 6 nm or less. In the load curve obtained from the surface roughness curve of the magnetic recording medium, the difference ΔBH [0.01, 0.8] between the height BH [0.01%] at which the load ratio is 0.01% and the height BH [0.8%] at which the load ratio is 0.8% The magnetic recording medium according to claim 5, wherein (= | BH [0.01%] − BH [0.8%] |) is 0.2 nm or more and 3 nm or less. In a magnetic recording medium in which a magnetic alloy layer, a protective layer, and a lubricating layer are formed in this order on a substrate via an underlayer, the load ratio in the load curve obtained from the surface roughness curve of the magnetic recording medium is 1%. The difference between the height BH [1%] and the height BH [50%] at which the load ratio is 50% is y (= | BH [1%]-BH [50%] |), and the load ratio is 15%. When the difference between the height BH [15%] and the height BH [50%] at which the load ratio is 50% is x (= | BH [15%]-BH [50%] |), the coordinates (x, The point represented by y) is a line connecting point (0.1, 1.6) and point (1, 3) on the xy plane, and a line connecting point (1, 3) and point (1, 4) , In the region surrounded by the line connecting point (1, 4) and point (0.1, 4) and the line connecting point (0.1, 4) and point (0.1, 1.6) Magnetic recording media. In a magnetic recording medium in which a magnetic alloy layer, a protective layer, and a lubricating layer are formed in this order on a substrate via an underlayer, the arithmetic average roughness (Ra) obtained from the surface roughness curve of the magnetic recording medium is 0.2 nm or more and 0.7 The magnetic recording medium according to claim 7, wherein the magnetic recording medium is nm or less. In a magnetic recording medium in which a magnetic alloy layer containing Co as a main component, a protective layer, and a lubricating layer are formed in this order on a substrate via a base layer, the base layer is formed of a substantially amorphous layer. 9. The magnetic recording medium according to claim 7, wherein the magnetic recording medium comprises a plurality of underlayers including a structure in which an underlayer and a second underlayer comprising a crystalline layer are laminated in this order. In the load curve obtained from the surface roughness curve of the substrate, the difference ΔBH [0.01, 50] between the height BH [0.01%] at which the load ratio is 0.01% and the height BH [50%] at which the load ratio is 50% ( The magnetic recording medium according to claim 1, wherein = | BH [0.01%] − BH [50%] |) is 3 nm or more and 6 nm or less. A magnetic recording medium; a drive unit for driving the magnetic recording medium; a magnetic head comprising a recording unit and a reproducing unit; means for moving the magnetic head relative to the magnetic recording medium; and ramping the magnetic head. In a magnetic disk apparatus having a mechanism unit, a signal input unit to the magnetic head, and a recording / reproducing signal processing unit for reproducing an output signal from the magnetic head, the reproducing units of the magnetic heads are magnetized in the mutual magnetization directions. And a magnetoresistive sensor including a plurality of conductive magnetic layers that cause a large change in resistance due to a relative change by an external magnetic field, and a conductive nonmagnetic layer disposed between the conductive magnetic layers, and 11. A magnetic disk device, wherein the magnetic recording medium is the magnetic recording medium according to claim 1.