Abstract: A magnetoresistive element includes a multilayer film configuration including: a tunnel insulation layer; and a pair of magnetic layers that are laminated with the tunnel insulation layer interposed therebetween. A resistance value of the magnetoresistive element varies with a relative angle between magnetic orientations of both of the magnetic layers, and at least one of the magnetic layers includes a magnetic film having a thermal expansion coefficient not greater than a value obtained by adding 2×10?6/K to a thermal expansion coefficient of the tunnel insulation layer. The thus configured magnetoresistive element can exert excellent thermal stability. The use of such a magnetoresistive element can realize a magnetic head, a magnetic memory element and a magnetic recording apparatus with excellent thermal stability.

Abstract: A magnetic switching device is provided, which has a configuration different from that of a conventional example and is capable of enhancing an energy conversion efficiency for changing the magnetized state of a magnetic substance. A magnetic memory using the magnetic switching device also is provided The magnetic switching device includes a magnetic layer, a transition layer magnetically coupled to the magnetic layer, and a carrier supplier including at least one selected from metal and a semiconductor. The transition layer and the carrier supplier are placed in such a manner that a voltage can be applied between the transition layer and the carrier supplier. The transition layer undergoes a non-ferromagnetism—ferromagnetism transition by the application of a voltage, and the magnetized state of the magnetic layer is changed by the transition of the transition layer.

Abstract: The present invention provides a thermal switching element that has a quite different configuration from that of a conventional technique and can control heat transfer by the application of energy, and a method for manufacturing the thermal switching element. The thermal switching element includes a first electrode, a second electrode, and a transition body arranged between the first electrode and the second electrode. The transition body includes a material that causes an electronic phase transition by application of energy. The thermal conductivity between the first electrode and the second electrode is changed by the application of energy to the transition body.

Abstract: The present invention provides a method for producing a magnetoresistive element including a tunnel insulating layer, and a first magnetic layer and a second magnetic layer that are laminated so as to sandwich the tunnel insulating layer, wherein a resistance value varies depending on a relative angle between magnetization directions of the first magnetic layer and the second magnetic layer.

Abstract: A magnetic head including a magnetic substrate for operating as a first electrode, a multi-layer film formed on a portion of the surface of the magnetic substrate an inter-layer insulating layer provided to cover side surfaces of the multi-layer film, a flux guide formed on surfaces of the multi-layer film and inter-layer insulating layers, a non-magnetic conductive layer formed on a surface of the flux guide, and a second electrode formed on a surface of the non-magnetic conductive layer, in which the multi-layer film includes a first magnetic layer formed on a portion of the surface of the magnetic substrate and includes a fixed layer, and a second magnetic layer including a non-magnetic layer formed on a surface of the first magnetic layer and a free layer formed on a surface of the non-magnetic layer.

Abstract: A magnetic switching device is provided, which has a configuration different from that of a conventional example and is capable of enhancing an energy conversion efficiency for changing the magnetized state of a magnetic substance. A magnetic memory using the magnetic switching device also is provided. The magnetic switching device includes a magnetic layer, a transition layer magnetically coupled to the magnetic layer, and a carrier supplier including at least one selected from metal and a semiconductor. The transition layer and the carrier supplier are placed in such a manner that a voltage can be applied between the transition layer and the carrier supplier. The transition layer undergoes a non-ferromagnetism-ferromagnetism transition by the application of a voltage, and the magnetized state of the magnetic layer is changed by the transition of the transition layer.

Abstract: A magnetoresistive element of the present invention includes a multilayer structure that includes a non-magnetic layer (3) and a pair of ferromagnetic layers (1, 2) stacked on both sides of the non-magnetic layer (3). A resistance value differs depending on a relative angle between the magnetization directions of the ferromagnetic layers (1, 2) at the interfaces with the non-magnetic layer (3). The composition of at least one of the ferromagnetic layers (1, 2) in a range of 2 nm from the interface with the non-magnetic layer (3) is expressed by (MxOy)1-zZz, where Z is at least one element selected from the group consisting of Ru, Os, Rh, Ir, Pd, Pt, Cu, Ag, and Au, M is at least one element selected from the group consisting of elements other than Z and O and includes a ferromagnetic metal, and x, y, and z satisfy 0.33<y/x<1.33, 0<x, 0<y, and 0≦z≦0.4. This magnetoresistive element can have excellent heat resistance and magnetoresistance characteristics.

Abstract: The present invention provides a method for producing a magnetoresistive element including a tunnel insulating layer, and a first magnetic layer and a second magnetic layer that are laminated so as to sandwich the tunnel insulating layer, wherein a resistance value varies depending on a relative angle between magnetization directions of the first magnetic layer and the second magnetic layer.

Abstract: A reader of the present invention reads the shape of the surface of an object and includes a magnetic displacement portion and a detecting portion. When the magnetic displacement portion comes into contact with the surface of the object, the magnetic state of the magnetic displacement portion differs depending on the shape of the surface. The detecting portion detects the magnetic state of the magnetic displacement portion. An authentication device of the present invention includes the reader, a memory, and a matching portion. The memory stores the shape of the surface of an object beforehand. The matching portion matches the shape read by the reader with the shape stored in the memory. The reader and the authentication device can use the magnetic displacement as a detection technique.

Abstract: A magnetic memory of the present invention includes two or more memory layers and two or more tunnel layers that are stacked in the thickness direction of the layers. The two or more memory layers are connected electrically in series. A group of first layers includes at least one layer selected from the two or more memory layers. A group of second layers includes at least one layer selected from the two or more memory layers. A resistance change caused by magnetization reversal in the group of first layers differs from a resistance change caused by magnetization reversal in the group of second layers.

Abstract: The present invention provides a magnetoresistive element that has excellent magnetoresistance characteristics over a conventional magnetoresistive element. The magnetoresistive element is produced by a method including heat treatment at 330° C. or more and characterized in that the longest distance from a centerline of a non-magnetic layer to the interfaces between a pair of ferromagnetic layers and the non-magnetic layer is not more than 10 nm. This element can be produced, e.g., by forming an underlying film on a substrate, heat-treating the underlying film at 400° C. or more, decreasing surface roughness by irradiating the surface of the underlying film with an ion beam, and forming the ferromagnetic layers and the non-magnetic layer. The longest distance is reduced relatively even when M1 (at least one element selected from Tc, Re, Ru, Os, Rh, Ir, Pd, Pt, Cu, Ag and Au) is added to the ferromagnetic layers in the range of 2 nm from the interfaces with the non-magnetic layer.

Abstract: A magnetoresistive element includes a multilayer film configuration including: a tunnel insulation layer; and a pair of magnetic layers that are laminated with the tunnel insulation layer interposed therebetween. A resistance value of the magnetoresistive element varies with a relative angle between magnetic orientations of both of the magnetic layers, and at least one of the magnetic layers includes a magnetic film having a thermal expansion coefficient not greater than a value obtained by adding 2×10−6/K to a thermal expansion coefficient of the tunnel insulation layer. The thus configured magnetoresistive element can exert excellent thermal stability. The use of such a magnetoresistive element can realize a magnetic head, a magnetic memory element and a magnetic recording apparatus with excellent thermal stability.

Abstract: The present invention provides a magnetic memory device that includes the following: a magnetoresistive element; a conductive wire for generating magnetic flux that changes a resistance value of the magnetoresistive element; and at least one ferromagnetic member through which the magnetic flux passes. The at least one ferromagnetic member forms a magnetic gap at a position where the magnetic flux passes through the magnetoresistive element. The following relationships are established: a) Ml≦2Lg; b) at least one selected from Lw/Ly≦5 and Ly/Lt≧5; and c) Ly≦1.0 &mgr;m, where Ml is a length of the magnetoresistive element that is measured in a direction parallel to the magnetic gap, Lg is a length of the magnetic gap, Lt is a thickness of the ferromagnetic member, Lw is a length of the ferromagnetic member in the direction of drawing of the conductive wire, and Ly is a length of a path traced by the magnetic flux in the ferromagnetic member.

Abstract: The present invention provides a magnetoresistive element that can suppress the characteristic degradation even after high-temperature heat treatment, specifically at 400° C. to 450° C. This element is manufactured by a method that includes the following processes in the indicated order: a film formation process for forming at least a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer on a substrate; a preheat process at 330° C. to 380° C. for not less than 60 minutes; and a heat treatment process at 400° C. to 450° C. This element has a resistance value that changes with a change in relative angle formed by the magnetization directions of the first ferromagnetic layer and the second ferromagnetic layer.

Abstract: A magnetoresistive element includes a pair of ferromagnetic layers and a non-magnetic layer arranged between the ferromagnetic layers. At least one of the ferromagnetic layers has a composition expressed by (MxLy)100−zRz at the interface with the non-magnetic layer. The non-magnetic layer includes at least one element selected from the group consisting of B, C, N, O, and P. Here, M is FeaCobNic, L is at least one element selected from the group consisting of Pt, Pd, Ir, and Rh, R is an element that has a lower free energy to form a compound with the element of the non-magnetic layer that is at least one selected from the group consisting of B, C, N, O, and P than does any other element included in the composition as M or L, and a, b, c, x, y, and z satisfy a+b+c=100, a≧30, x+y=100, 0<y≦35, and 0.1≦z≦20. This element can provide a high MR ratio. A method for manufacturing a magnetoresistive element includes a first heat treatment process at 200° C.

Abstract: A magnetic recording medium includes a magnetic film for signal recording and a film containing M2Oy as a main component that is magnetically exchange-coupled to the magnetic film to increase the effective V and Ku of the magnetic film and to suppress thermal fluctuation. Herein, M is at least one element selected from Fe, Co, Ni, alkaline earth elements, Y, lanthanoids and Bi and includes at least one selected from Fe, Co and Ni as an essential element, and y is a value satisfying 2.8<y<3.2.

Abstract: A magnetoresistance effect element includes a free layer, in which a magnetization direction thereof is easily rotated in response to an external magnetic field, a first non-magnetic layer, and a first pinned layer provided on a side opposite to the free layer of the first non-magnetic layer, in which a magnetization direction of the first pinned layer is not easily rotated in response to the external magnetic field. At least one of the first pinned layer and the free layer includes a first metal magnetic film contacting the first non-magnetic layer, and a first oxide magnetic film.

Abstract: The present invention provides a magnetoresistive element that can suppress the characteristic degradation even after high-temperature heat treatment, specifically at 400° C. to 450° C. This element is manufactured by a method that includes the following processes in the indicated order: a film formation process for forming at least a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer on a substrate; a preheat process at 330° C. to 380° C. for not less than 60 minutes; and a heat treatment process at 400° C. to 450° C. This element has a resistance value that changes with a change in relative angle formed by the magnetization directions of the first ferromagnetic layer and the second ferromagnetic layer.

Abstract: A magneto-resistive element includes a magnetic substrate; a magnetic layer; and a non-magnetic layer provided between the magnetic substrate and the magnetic layer.

Abstract: The present invention provides a magnetoresistive (MR) element that is excellent in MR ratio and thermal stability and includes at least one magnetic layer including a ferromagnetic material M—X expressed by M100−aXa. Here, M is at least one selected from Fe, Co and Ni, X is expressed by X1bX2cX3d (X1 is at least one selected from Cu, Ru, Rh, Pd, Ag, Os, Ir, Pt and Au, X2 is at least one selected from Al, Sc, Ti, V, Cr, Mn, Ga, Ge, Y, Zr, Nb, Mo, Hf, Ta, W, Re, Zn and lanthanide series elements, and X3 is at least one selected from Si, B, C, N, O, P and S), and a, b, c and d satisfy 0.05≦a≦60, 0≦b≦60, 0≦c≦30, 0≦d≦20, and a=b+c+d.