Abstract: An electrolytic copper foil having higher electrical conductivity, and a method for producing the same are provided. The electrolytic copper foil according the present invention has a carbon content of 5 ppm or less, a sulfur content of 3 ppm or less, an oxygen content of 5 ppm or less, and a nitrogen content of 0.5 ppm or less; has a total content of carbon, sulfur, oxygen, nitrogen, and hydrogen of 15 ppm or less; and has a number of grains of 8.0 to 12.0/?m2, the number of grains changing to 0.6 to 1.0/?m2 by heating the electrolytic copper foil at 150° C. for 1 hour. A method for producing this electrolytic copper foil includes cleaning a copper raw material; dissolving the copper raw material after the cleaning to obtain an electrolytic solution having a total organic carbon (TOC) of 10 ppm or less; and electrolyzing the electrolytic solution to obtain the electrolytic copper foil.

Abstract: An information-recording medium includes first and second recording layers each of which is formed of a phase-change material containing Bi, Ge, and Te, wherein the first recording layer is arranged nearer to a light-incident side of the laser beam than the second recording layer; a composition of Bi, Ge, and Te contained in the second recording layer is within a composition range surrounded by composition points B2, C2, D2, D6, C6, and B6 on a triangular composition diagram of Bi, Ge, and Te; and a difference (???) between a composition ? of Bi in the first recording layer and a composition ? of Bi in the second recording layer is ?1.0 to 3.0 at. %. Thus, there is provided a two-layered information-recording medium with high recording-data reliability and excellent repeated-data recording durability.

Abstract: A magnetic recording medium based on the perpendicular magnetic recording system includes a substrate; a back layer which is formed on the substrate and which is formed of a soft magnetic material; an in-plane magnetized layer which is formed on the back layer and which has in-plane magnetization; and a recording layer which is formed on the in-plane magnetized layer and which has perpendicular magnetization, wherein the in-plane magnetized layer has a coercivity in an in-plane direction larger than a magnetic field generated by residual magnetization in a perpendicular direction of the recording layer. The influence on the reproduction output, caused by the mirror image effect of the soft magnetic back layer is reduced in wide range recording densities, thereby improving the resolution by decreasing the difference between the reproduction outputs of the magnetic recording medium at the low recording density and at the high recording density.

Abstract: A magnetic recording medium in which the medium noise is reduced and information can be recorded at a high S/N level, and a method for producing the magnetic recording medium are provided. A magnetic recording apparatus, which is excellent in thermal stability and which makes it possible to perform the high density recording, is provided. When films are formed for the magnetic recording medium based on the perpendicular magnetic recording method, the content of B in a seed layer is made sufficiently larger than the content of B in a recording layer. Accordingly, B is diffused from the seed layer to the recording layer to facilitate the segregation of B at the crystal grain boundary in the recording layer. Thereby, the magnetic interaction between the crystal grains in the recording layer is further reduced. Thus, it is possible to greatly reduce the transition noise.

Abstract: A recording and reproducing apparatus including a recording magnetic head and a reproducing magnetic head with their floating height lowered for high density recordation and reproduction is provided. An information recording medium is provided on which it is possible to densely record information and from which it is possible to densely reproduce information by lowering the floating height of the recording and reproducing heads. The information recording medium includes a flat substrate and a recording layer provided on the substrate. Servo patterns and management information are recorded as magnetic marks on the recording layer in advance by a servo writer or the like. Because the substrate needs no recessed and embossed patterns formed in it, the slider of the recording and reproducing apparatus can be floated at a constant floating height lower than conventionally over the whole area of the medium.

Abstract: A magnetic recording medium based on the perpendicular magnetic recording system includes a substrate; a back layer which is formed on the substrate and which is formed of a soft magnetic material; an in-plane magnetized layer which is formed on the back layer and which has in-plane magnetization; and a recording layer which is formed on the in-plane magnetized layer and which has perpendicular magnetization, wherein the in-plane magnetized layer has a coercivity in an in-plane direction larger than a magnetic field generated by residual magnetization in a perpendicular direction of the recording layer. The influence on the reproduction output, caused by the mirror image effect of the soft magnetic back layer is reduced in wide range recording densities, thereby improving the resolution by decreasing the difference between the reproduction outputs of the magnetic recording medium at the low recording density and at the high recording density.

Abstract: A magnetic recording medium 100 comprises, on a substrate 1, a soft magnetic layer 3, a seed layer 5, and a recording layer 6 having an artificial lattice structure. The seed layer 5 is formed of Pd and one selected from the group consisting of Si, B, C, and Zr. Accordingly, the magnetic exchange coupling force of the recording layer 6 in the in-plane direction can be weakened. Minute recording magnetic domains can be formed in the recording layer 6, and the magnetization transition area is distinct as well. Thus, the medium noise is reduced. That is, reproduction can be performed with a low medium noise even when information is recorded at a high density. A magnetic storage apparatus, which is provided with the magnetic recording medium as described above, can achieve an areal recording density of 150 Gigabits/square inch.

Abstract: The object of the present invention is to provide an artificial lattice multilayer film medium having both the excellent signal-noise ratio (S/N) and the high coercive force and demagnetization resistance by reconciling the reduction of transition noise and the high magnetic anisotropy, and a magnetic storage device having a high S/N and a high demagnetization resistance even at a high areal recording density by using the artificial lattice multilayer film medium. The magnetic recording medium of the present invention is a magnetic recording medium comprising at least a soft magnetic layer, a seed layer and a recording layer having a multilayer film structure comprising alternately laminated Co and Pd, these layers being successively laminated on a nonmagnetic substrate, where the recording layer comprises an aggregate of fcc crystal grains, the average value of (111) interplanar spacing of the fcc crystals is not more than 2.

Abstract: A magnetic recording medium comprises, on a substrate, a soft magnetic layer, a first seed layer, a second seed layer, and a recording layer having an artificial lattice structure. The first seed layer contains oxide of Fe. The second seed layer contains one of Pd and Pt, Si, and N. The magnetic exchange coupling force in the in-plane direction of the recording layer is weakened by the first seed layer and the second seed layer. Accordingly, minute recording magnetic domains can be formed in the recording layer, and the magnetization transition area is distinct as well. Even when information is recorded at a high density, the information can be reproduced with low noise. A magnetic storage apparatus, which is provided with such a magnetic recording medium, makes it possible to achieve an areal recording density of 150 gigabits/square inch.

Abstract: A magnetic disk comprises, on a substrate, a soft magnetic layer, a seed layer, and a recording layer having an artificial lattice structure. The soft magnetic layer is formed of Co and B, and the seed layer is formed of Pd and B. The structure can reduce the magnetic exchange coupling force in the in-plane direction acting between crystal grains of the recording layer. Therefore, minute recording magnetic domains can be formed in the recording layer, the magnetization transition area is distinct, and the medium noise is reduced. Even when information is recorded at a high density, the information can be reproduced with low medium noise. The thermal stability is also excellent, because the recording layer composed of the artificial lattice structure has high magnetic anisotropy.

Abstract: A magnetic recording medium in which the medium noise is reduced and information can be recorded at a high S/N level, and a method for producing the magnetic recording medium are provided. A magnetic recording apparatus, which is excellent in thermal stability and which makes it possible to perform the high density recording, is provided. When films are formed for the magnetic recording medium based on the perpendicular magnetic recording method, the content of B in a seed layer is made sufficiently larger than the content of B in a recording layer. Accordingly, B is diffused from the seed layer to the recording layer to facilitate the segregation of B at the crystal grain boundary in the recording layer. Thereby, the magnetic interaction between the crystal grains in the recording layer is further reduced. Thus, it is possible to greatly reduce the transition noise.

Abstract: A magnetic recording medium comprises, on a substrate, a soft magnetic layer, a first seed layer, a second seed layer, and a recording layer having an artificial lattice structure. The first seed layer contains oxide of Fe. The second seed layer contains one of Pd and Pt, Si, and N. The magnetic exchange coupling force in the in-plane direction of the recording layer is weakened by the first seed layer and the second seed layer. Accordingly, minute recording magnetic domains can be formed in the recording layer, and the magnetization transition area is distinct as well. Even when information is recorded at a high density, the information can be reproduced with low noise. A magnetic storage apparatus, which is provided with such a magnetic recording medium, makes it possible to achieve an areal recording density of 150 gigabits/square inch.

Abstract: A magnetic recording medium of the present invention comprises an MgO layer 2, a first control layer 3, a second control layer 4, a magnetic layer 5, and a protective layer 6 which are provided in this order on a substrate 1. The MgO layer is formed by means of the ECR sputtering method. Accordingly, this layer is crystallized in the hexagonal system, and crystals are successfully oriented in a certain azimuth. Two or more layers of metal control layers are formed on the MgO layer by using materials and compositions so that the difference in lattice constant with respect to the magnetic layer is not more than 5%. Owing to the presence of the control layers, the magnetic layer is epitaxially grown in a well-suited manner while reflecting the structure of the MgO layer, making it possible to realize the orientation of (11.0) of Co which is preferred to perform the high density recording in the magnetic layer.

Abstract: A magnetic recording medium comprises, on a substrate, a soft magnetic layer, a first seed layer, a second seed layer, and a recording layer having an artificial lattice structure. The first seed layer contains oxide of Fe. The second seed layer contains one of Pd and Pt, Si, and N. The magnetic exchange coupling force in the in-plane direction of the recording layer is weakened by the first seed layer and the second seed layer. Accordingly, minute recording magnetic domains can be formed in the recording layer, and the magnetization transition area is distinct as well. Even when information is recorded at a high density, the information can be reproduced with low noise. A magnetic storage apparatus, which is provided with such a magnetic recording medium, makes it possible to achieve an areal recording density of 150 gigabits/square inch.

Abstract: A magnetic recording medium 100 comprises, on a substrate 1, a soft magnetic layer 3, a seed layer 5, and a recording layer 6 having an artificial lattice structure. The seed layer 5 is formed of Pd and one selected from the group consisting of Si, B, C, and Zr. Accordingly, the magnetic exchange coupling force of the recording layer 6 in the in-plane direction can be weakened. Minute recording magnetic domains can be formed in the recording layer 6, and the magnetization transition area is distinct as well. Thus, the medium noise is reduced. That is, reproduction can be performed with a low medium noise even when information is recorded at a high density. A magnetic storage apparatus, which is provided with the magnetic recording medium as described above, can achieve an areal recording density of 150 Gigabits/square inch.

Abstract: A magnetic recording medium comprises, on a substrate, a soft magnetic layer, a first seed layer, a second seed layer, and a recording layer having an artificial lattice structure. The first seed layer contains oxide of Fe. The second seed layer contains one of Pd and Pt, Si, and N. The magnetic exchange coupling force in the in-plane direction of the recording layer is weakened by the first seed layer and the second seed layer. Accordingly, minute recording magnetic domains can be formed in the recording layer, and the magnetization transition area is distinct as well. Even when information is recorded at a high density, the information can be reproduced with low noise. A magnetic storage apparatus, which is provided with such a magnetic recording medium, makes it possible to achieve an areal recording density of 150 gigabits/square inch.