Abstract: [Object] Provided is a technology that is capable of further improving a recording density of data.

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: The present invention provides a magnetic sheet with improved resistance to folding while maintaining good magnetic characteristics and reliability; a method for producing the magnetic sheet; an antenna; and a portable communication device. A magnetic sheet of the present invention includes a flat magnetic powder, and a resin binder capable of dissolving in a solvent, wherein the magnetic sheet has a gradient of the content ratio of the magnetic powder to the resin binder in a thickness direction thereof, wherein, in use, the magnetic sheet is folded so that, of the front and back surfaces thereof, one surface whose magnetic powder content is lower than that of the other is folded inward, and wherein the difference in glossiness measured at a light-incident angle of 60° between the front and back surfaces is 9.4 or more.

Abstract: A magnetic recording medium capable of attaining high in-plane recording density of 100 Mbits or more per 1 mm2 is provided. Magnetic recording medium is provided in which underlayers, a first magnetic layer, a first intermediate layer, a second magnetic layer, a second intermediate layer, a third magnetic layer, a protection layer and lubrication layer are formed in this order above a substrate. Each of the third magnetic layer and the second magnetic layer comprises a Co-based alloy containing at least Pt, Cr and B. The concentration of Pt contained in the second magnetic layer is not more than that in the third magnetic layer.

Abstract: A magnetic recording medium comprising a non-magnetic support; at least one lower magnetic layer containing magnetic powder and a binder resin, which is formed on one side of the non-magnetic support with or without a non-magnetic primer layer interposed between the non-magnetic support and the lower magnetic layer; at least one non-magnetic intermediate layer containing non-magnetic powder and a binder resin, which is formed on the lower magnetic layer; at least one upper magnetic layer containing magnetic powder and a binder resin, which is formed on the non-magnetic intermediate layer; and a back layer which is formed on the other side of the non-magnetic support, characterized in that the magnetic powder contained in the uppermost magnetic layer of the upper magnetic layer is iron type magnetic powder which comprises substantially spherical or ellipsoidal particles with a number-average particle diameter of 5 to 50 nm and an average axial ratio of 1 to 2, each of said particles containing iron or containi

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.