Abstract: A magnetic stack includes a substrate and a magnetic recording layer disposed over the substrate. The magnetic recording layer comprises magnetic crystalline grains and a segregant disposed between grain boundaries of the crystalline grains. One or both of the magnetic crystalline grains and the segregant are doped with a rare earth or transition metal dopant in an amount that provides the magnetic recording layer with a magnetic damping value, ?, between about 0.1 to about 1.

Abstract: A shallow trench discrete track media structure is fabricated by etching a magnetic recording layer to provide a plurality of discrete magnetic data tracks separated by shallow trenches. Each shallow trench has a trench floor formed at a depth in the magnetic recording layer that is less than the thickness of the magnetic recording layer. Exposed regions of the magnetic recording layer beneath the trench floor are reacted with reactive plasma to diminish the magnetic moment of the exposed regions.

Abstract: A magnetic tape produced by cutting a magnetic sheet with a wide breadth into a tape having a predetermined width using a cutting device, in which the magnetic sheet has a magnetic layer containing magnetic powder and a hinder formed on one surface of a non-magnetic substrate having a thickness of 4 ?m or less, and a center line average height (Ra) along a roughness curve of a cut edge of the magnetic tape is from 0.08 to 0.25 ?m.

Abstract: The invention provides a magnetic disk that solves (1) a problem of cross-talk that cannot be solved even by an existing thermally assisted recording method or a discrete method (DTM or the like), (2) a problem of surface flatness, which an existing embedding type DTM or the like has, and (3) a problem of a difference in thermal expansion coefficient between materials when a thermally assisted method is applied to the DTM, and that (4) does not necessitate a special medium structure, and is excellent in a surface flatness and economically and functionally high in realizability. A DTM manufactured by ion implantation is excellent in the surface flatness, and can solve the cross-talk problem by conducting the thermally assisted recording at a temperature between a Curie temperature (Tcn) of a portion where ions are implanted (non-recording region) and a Curie temperature (Tcr) of a portion where ions are not implanted (recording region).

Abstract: Ion irradiation is applied to the surface of a recording layer which has a granular structure containing ferromagnetic particles which are composed of an L10 ordered alloy and a non-magnetic intergranular layer, thereby the ferromagnetic particles in the side of the substrate are transformed into an L10 ordered alloy having a high magnetic anisotropy, and the ferromagnetic particles in the side of the surface of the medium are transformed into an A1 disordered alloy having a low magnetic anisotropy.

Abstract: A shallow trench discrete track media structure is fabricated by etching a magnetic recording layer to provide a plurality of discrete magnetic data tracks separated by shallow trenches. Each shallow trench has a trench floor formed at a depth in the magnetic recording layer that is less than the thickness of the magnetic recording layer. Exposed regions of the magnetic recording layer beneath the trench floor are reacted with reactive plasma to diminish the magnetic moment of the exposed regions.

Abstract: A magnetic tape produced by cutting a magnetic sheet with a wide breadth into a tape having a predetermined width using a cutting device, in which the magnetic sheet has a magnetic layer containing magnetic powder and a binder formed on one surface of a non-magnetic substrate having a thickness of 4 ?m or less, and a center line average height (Ra) along a roughness curve of a cut edge of the magnetic tape is from 0.08 to 0.25 ?m.

Abstract: A magnetic recording medium is provided that comprises a non-magnetic support and at least one magnetic layer above the support, the magnetic layer comprising a ferromagnetic powder dispersed in a binder, and the binder comprising a polyurethane resin having a weight-average molecular weight of 200,000 to 400,000. There is also provided a magnetic recording medium that comprises a non-magnetic support, a non-magnetic layer above the support, the non-magnetic layer comprising a non-magnetic powder dispersed in a binder, and at least one magnetic layer above the non-magnetic layer, the magnetic layer comprising a ferromagnetic powder dispersed in a binder and the binder of the magnetic layer and/or the non-magnetic layer comprising a polyurethane resin having a weight-average molecular weight of 200,000 to 400,000.

Abstract: The present invention provides a magnetic recording medium comprising a magnetic layer with excellent surface smoothness, which comprises a thin film magnetic layer of thickness in a range from 0.03 to 0.30 ?m that is ideal for short wavelength recording, and displays superior electromagnetic conversion characteristics. The magnetic recording medium comprises a magnetic layer containing at least a ferromagnetic powder and a binder resin on one surface of a non-magnetic support, wherein the thickness of the magnetic layer is within a range from 0.03 to 0.30 ?m, and the number of concavities with a depth of 30 nm or greater in the surface of the magnetic layer is 5 per 1 cm2 of surface area or less. Preferably, the value of the average depth Rv6 of the surface of the magnetic layer, as measured by a contact type surface roughness meter, is 12 nm or less.

Abstract: Disclosed are a magnetic tape capable of being wound regularly, and an apparatus and a method by which the tape is wound regularly. The tape-shaped recording medium, which includes a tape-shaped support body and a recording layer being formed on a surface of the support body, is curved laterally over its whole length and said tape-shaped recording medium being curved laterally over its whole length and having a surface arching across a whole width of the medium. Furthermore, it is preferable that a curved amount of the medium ranges from 0.5 mm/m to 4.0 mm/m and an arched amount of the medium ranges from 0.3 mm to 2.0 mm.

Abstract: A leader tape where an non-magnetic under layer that contains a powder and a binder and a magnetic upper layer are sequentially laminated on at least one face of a support, in which F5 values of the support in a machine direction (MD) and in a transverse direction (TD) are from 80 to 120 MPa respectively, the F5 value in MD is larger than that in TD, and a difference between the F5 value in MD and that in TD is 15 MPa or less.

Abstract: A leader tape comprising a support and a coating layer containing powder and a binder, wherein at least one surface of the leader tape has a center line average surface roughness (Ra) of from 10 to 60 nm, and depression hardness (DH) defined by the following equation (1) of from 60 to 140 kg/mm2 (0.588 to 1.372 GPa): DH=3.7926×10?2[Pmax/(Hmax)2](kg/mm2) ??(1) wherein Pmax is a maximum load and Hmax is a maximum displacement amount of an indenter.

Abstract: A magnetic recording medium including a polymer support having thereon at least one magnetic layer containing a ferromagnetic metal powder having an average major axis length of from 20 to 100 nm or a ferromagnetic hexagonal ferrite powder having an average tabular diameter of from 5 to 40 nm and a binder, the polymer support having an intrinsic viscosity of from 0.47 to 0.51 dL/g, a Young's modulus in the machine direction of from 7.0 to 8.6 GPa, a Young's modulus in the transverse direction of from 5.4 to 8.0 GPa, and a breaking strength in the transverse direction of from 370 to 450 MPa.

Abstract: The present invention provides a magnetic recording medium comprising a magnetic layer with excellent surface smoothness, which comprises a thin film magnetic layer of thickness in a range from 0.03 to 0.30 ?m that is ideal for short wavelength recording, and displays superior electromagnetic conversion characteristics. The magnetic recording medium comprises a magnetic layer containing at least a ferromagnetic powder and a binder resin on one surface of a non-magnetic support, wherein the thickness of the magnetic layer is within a range from 0.03 to 0.30 ?m, and the number of concavities with a depth of 30 nm or greater in the surface of the magnetic layer is 5 per 1 cm2 of surface area or less. Preferably, the value of the average depth Rv6 of the surface of the magnetic layer, as measured by a contact type surface roughness meter, is 12 nm or less.

Abstract: The present invention provides a magnetic recording medium which can record both digital and analog signals by, e.g., VTR for commercial use and improve their electromagnetic conversion characteristics. A magnetic recording medium comprises a nonmagnetic support, and first and second magnetic layers comprised respectively of magnetic powder (A) and (B), wherein the first and second magnetic layers are formed on the nonmagnetic support in this order, wherein the magnetic powder (A) and (B) have the following characteristics: saturation magnetization ?s(A) ?80 to 150 Am2/kg; coercive force Hc(A) ?90 to 180 kA/m, saturation magnetization ?s(B) 100 to 200 Am2/kg, coercive force Hc(B) 100 to 200 kA/m, wherein the first and second magnetic layers satisfy the below relationships and have thickness T(A) and T(B) in the below ranges: ?s(A)/?s(B)?1.0, Hc(A)/Hc(B)?1.0, 1.0 ?m?T(A)?4.0 ?m, 0.01 ?m?T(B)?0.5 ?m.

Abstract: The present invention provides a magnetic recording medium which can record both digital and analog signals by, e.g., VTR for commercial use and improve their electromagnetic conversion characteristics. A magnetic recording medium comprises a nonmagnetic support, and first and second magnetic layers comprised respectively of magnetic powder (A) and (B), wherein the first and second magnetic layers are formed on the nonmagnetic support in this order, wherein the magnetic powder (A) and (B) have the following characteristics: saturation magnetization ?s(A): 80 to 150 Am2/kg; coercive force Hc(A): 90 to 180 kA/m, saturation magnetization ?s(B): 100 to 200 Am2/kg, coercive force Hc(B): 100 to 200 kA/m, wherein the first and second magnetic layers satisfy the below relationships and have thickness T(A) and T(B) in the below ranges: ?s(A)/?s(B)?1.0,Hc(A)/Hc(B)?1.0, 1.0 ?m?T(A)?4.0 ?m, 0.01 ?m?T(B)?0.5 ?m.