Abstract: A phase change optical recording medium according to an embodiment of this invention includes a substrate, a reflecting layer which reflects a light beam, a phase change recording layer which is arranged between the substrate and the reflecting layer and changes between a crystalline state and an amorphous state when irradiated with the light beam, a first dielectric layer which is arranged between the substrate and the reflecting layer, and a second dielectric layer which is arranged between the substrate and the first dielectric layer and has a thermal conductivity lower than that of the first dielectric layer.

Abstract: There is provided an optical recording medium capable of preventing cross erase and increasing its recording density. The optical recording medium includes: a reflecting film; a first transparent film provided on the reflecting film; a first semitransparent film provided on the first transparent film; a second transparent film provided on the first semitransparent film; a recording film provided on the second transparent film, the recording film being capable of reversibly changing an atomic arrangement; and a third transparent film provided on the recording film. The first semitransparent film has a complex refractive index of n−k satisfying relationships of 0<n<1 and 1<k, and a product of a thickness d (nm) of the first semitransparent film and an extinction coefficient k of the complex refractive index is d×k≦44.

Abstract: An optical disk exhibits enhanced overwrite overwrite characteristics and cross-erase suppression. An optical disk includes a flattening layer formed on a substrate; a reflective layer formed on the flattening layer; a phase-change optical recording layer formed on the reflective layer, the recording layer being changeable between crystalline and amorphous states, portions of the recording layer to become the crystalline state exhibiting reflectivity lower than other portions of the recording layer to become the amorphous state; a plurality of dielectric layers stacked on the recording layer, at least two of the dielectric layers having different optical constants; and a light absorbing layer formed at one location selected from a location between the recording layer and the lowermost layer of the dielectric layers, a location between any of two adjacent layers of the dielectric layers, and a location on the uppermost layer of the dielectric layers.

Abstract: A phase change recording medium comprising an as-deposited first recording layer configured to undergo a reversible phase change between an amorphous state and a crystalline state due to light irradiation and thereby change an optical characteristic. The as-deposited first recording layer includes a plurality of fine nuclei having an average size of 0.5 nm to 4 nm in the amorphous state.

Abstract: An optical information recording medium includes a substrate, first information recording layer, and second information recording layer. The first information recording layer includes a recording film, first dielectric film whose complex index has a real part n1, second dielectric film whose complex index has a real part n2, and third dielectric film whose complex index has a real part n3. Relationships n1>n2 and n3>n2 are satisfied.

Abstract: An optical information recording medium of this invention includes a substrate, a light incident surface, a first reflecting layer formed between the substrate and the light incident surface, a second reflecting layer formed between the first reflecting layer and the light incident surface and stacked on the first reflecting layer, the second reflecting layer being made of the same material as that of the first reflecting layer, and a phase change optical recording layer formed between the second reflecting layer and the light incident surface, the phase change optical recording layer transiting between a crystal state and an amorphous state when irradiated with a light beam.

Abstract: It is an object to improve the recording transfer rate of a phase change recording medium, to reduce the producing costs of the medium, to greatly increase the degree of freedom for the selection of the substrate of the medium, particularly to provide a medium having a structure of Rc<Ra, and to increase the storage capacity of the medium. In order to accomplish this object, a medium, wherein the initial state is an amorphous state immediately after sputtering, has a structure having a unique short-range order. In addition, there is provided a medium wherein the distribution of the number of crystal grains with respect to grain sizes has a plurality of maximum values. Moreover, when a recording operation is carried out by laser beams, an amorphous state band part is formed between tracks. In addition, the thermal conductivity of a recording layer is in a unique range, and contains Kr or Xe in a specific range.

Abstract: In a phase change optical recording medium, by determining heat conductivity relatively higher in one of interference layers on and under the recording layer, heat absorbed into the recording layer can be released moderately through an interference layer. Thereby, cross erasure caused by heating of adjacent tracks can be prevented, and at the same time, excessive heat radiation is prevented from a part of the recording layer nearer to the substrate to thereby maintain appropriate heat in the recording layer. As a result, cross-erasure is prevented, and data can be rewritten with the supply of typical recording/erasure power.

Abstract: A phase change recording medium comprises a substrate, an interference layer formed on the substrate and a recording layer formed on the interference layer. In this, the reflectance of the crystalline region in the recording layer is lower than that of amorphous region therein, and the interference layer comprises at least three layers of which the dielectric constant differs from that of the adjacent layers. With that constitution, the optical characteristics and the thermal characteristics of the medium are all optimized.

Abstract: A magnetic recording apparatus includes a magnetic recording medium including a substrate and a magnetic recording layer formed on the substrate and having a structure in which magnetic grains are dispersed in a nonmagnetic matrix, a means for recording magnetic information on the magnetic recording medium, and a means for reproducing magnetic information from the magnetic recording medium wherein the magnetic grains are separated from the substrate by a part of the matrix and form a substantially single layer parallel to the main surface of the substrate.

Abstract: A magnetic element comprises a granular magnetic film which has ferromagnetic fine particles dispersed in a dielectric matrix and does not display superparamagnetism and further possesses a finite coercive force, and a ferromagnetic film. A granular magnetic film and a ferromagnetic film are stacked or arrayed along one surface of a substrate and constitutes a ferromagnetic tunnel junction film. In the ferromagnetic tunnel junction film, the granular magnetic film functions as a barrier. Of the granular magnetic film and the ferromagnetic film, by varying spin direction of one ferromagnetic film through an external magnetic field, a giant magnetoresistance effect is manifested. Such a magnetic element is characterized in that magnetoresistance change rate is large, saturation magnetic field is small, resistance of the element can be controlled to an appropriate value, performance is small in its variation and stable.

Abstract: A phase change optical recording medium includes a phase change optical recording layer which transits between two states of the crystalline state and the amorphous state when irradiated with light, and a heat adjustment layer which is formed adjacent to the phase change optical recording layer and abruptly increases or decreases thermal conductivity with increasing temperature upon irradiation of recording light. This phase change optical recording medium can decrease the size of the recording mark and makes high-density recording possible.

Abstract: A magnetic recording medium comprising a substrate and a magnetic film formed on the substrate, the magnetic film including magnetic crystal grains in a non-magnetic matrix and satisfying the condition given below:d.sup.2 .multidot.t.multidot.Ir/(v.multidot.Isb).gtoreq.0.75wheret: a thickness of the magnetic film;Ir: a remanent magnetization moment of the magnetic film;d: an average particle size of the magnetic crystal grains in an intra-film direction of the magnetic film; andv.multidot.Isb: an activated magnetization moment of the magnetic film.

Abstract: A phase change optical recording medium having a structure that a phase change optical recording layer and other layers are stacked, wherein the optical recording layer has a microstructure that particles of optical recording material are dispersed in a matrix made from a dielectric, and wherein the optical recording layer meets the condition of Ama<Amc with respect to Maxwell Garnett absorption, where Ama and Amc are the magnitude of Maxwell Garnett absorption of the optical recording layer in the case where the particles are amorphous and crystalline, respectively, so that the optical recording layer meets the condition of Aa*.ltoreq.Ac* with respect to effective absorbance, where Aa* and Ac* are the effective absorbance of the optical recording layer in the case where the particles are amorphous and crystalline, respectively.

Abstract: A magnetoresistance effect element comprises a magnetic body obtained by dispersing magnetic metal particles containing at least one magnetic element selected from the group consisting of Fe, Co, and Ni in a semiconductor matrix.

Abstract: A magnetic device, comprises a first magnetic layer; a second magnetic layer on the magnetic layer and having a coercive force smaller than that of the first magnetic layer; a semiconductor layer between the first and second magnetic layers so that photo-induced magnetism occurs between the first and second magnetic layers when the semiconductor layer is irradiated with light, a third magnetic layer on the second magnetic layer, the third magnetic layer having a coercive force larger than the coercive force of the second magnetic layer, and a second semiconductor layer between the second and third magnetic layers, magnetism being induced between the second and third magnetic layers when the second semiconductor layer is irradiated with light.

Abstract: Disclosed is an artificial multilayer in which ferromagnetic layers and nonmagnetic layers are alternatively laminated, wherein a uniaxial magnetic anisotropy is introduced into the ferromagnetic layers in a predetermined direction, thereby controlling the gradient of the relative change of resistivity to the change of external magnetic field. The uniaxial magnetic anisotropy is introduced into the ferromagnetic layers by applying a magnetic field along the surface of ferromagnetic layers during the formation thereof.

Abstract: There is disclosed a magnetoresistance effect element including a multilayer constituted by a magnetic layers in which fine magnetic metal particles of crystalline or amorphous containing at least one element of Fe, Co, and Ni are dispersed in a matrix containing at least one element selected from the group consisting of noble metals and Cu, and non-magnetic layers containing a noble metal.

Abstract: Disclosed is an artificial multilayer in which ferromagnetic layers and nonmagnetic layers are alternatively laminated, wherein a uniaxial magnetic anisotropy is introduced into the ferromagnetic layers in a predetermined direction, thereby controlling the gradient of the relative change of resistivity to the change of external magnetic field. The uniaxial magnetic anisotropy is introduced into the ferromagnetic layers by applying a magnetic field along the surface of ferromagnetic layers during the formation thereof.