Abstract: A nonvolatile memory element in which Rb1-yMbyMnO3 having higher insulation properties than Ra1-xMaxMnO3 is inserted between the Ra1-xMaxMnO3 and a metal having a shallow work function or a low electronegativity in order to improve resistance change properties and switching properties and to control the resistance change properties. (In the formulas, Ra and Rb represent rare earth elements and are solid solutions of one or more types of rare earth elements. Average ionic radius of the Rb is smaller than that of the Ra. Ma and Mb represent alkaline earth metals and are solid solutions of one or more types of alkaline earth metals. 0<x, y<1).

Abstract: A multiferroic element having a simple structure in which orientation of electric polarization or magnetization of a solid state material can be controlled by applying a magnetic field or an electric field, respectively. By applying an external magnetic field to a multiferroic solid state material that exhibits ferroelectricity and ferromagnetism having a spin structure such that the orientation of spin is rotating along the outside surface of a cone (apex angle ? at the top of the cone is in a range of 0<??90 degrees), an electric polarization with orientation substantially perpendicular to the direction of the externally applied magnetic field can be controlled. Meanwhile, by applying an external electric field to the multiferroic solid state material, a magnetization with an orientation substantially perpendicular to the direction of the externally applied electric field can be controlled.

Abstract: A nonvolatile memory element in which Rb1-yMbyMnO3 having higher insulation properties than Ra1-xMaxMnO3 is inserted between the Ra1-xMaxMnO3 and a metal having a shallow work function or a low electronegativity in order to improve resistance change properties and switching properties and to control the resistance change properties. (In the formulas, Ra and Rb represent rare earth elements and are solid solutions of one or more types of rare earth elements. Average ionic radius of the Rb is smaller than that of the Ra. Ma and Mb represent alkaline earth metals and are solid solutions of one or more types of alkaline earth metals. 0<x, y<1).

Abstract: Provided is a material composition which allows a nonvolatile memory element made of a perovskite-type transition metal oxide having the CER effect to be formed of three elements, which comprises an electric conductor having a shallow work function or a small electronegativity, such as Ti, as an electrode and a rare earth-copper oxide comprising one type of rare earth element, copper and oxygen, such as La2CuO4, as a material constituting a heterojunction with the electric conductor.

Abstract: Disclosed is a high-pressure generation apparatus, which comprises a pair of columnar-shaped anvils disposed in opposed relation to one another to define a pressure-generating space therebetween. The anvils are adapted to be applied with a load therebetween to generate a high pressure in the pressure-generating space. Each of the anvils has a top portion formed in an approximately circular truncated cone shape, and the top portion has a central region formed with a depression having a side surface which extends obliquely outward. The high-pressure generation apparatus also includes a cylindrical capsule disposed in a central area of the pressure-generating space, and a laminated member formed by alternately laminating a doughnut-shaped metallic thin plate and a doughnut-shaped insulating member along the outer periphery of the capsule. The improved shape of the depression makes it possible to significantly reduce damages of the components.

Abstract: The present invention provides a rare earth element-doped optical fiber amplifier having a function which allows to omit an optical isolator component, and a method for providing the optical non-reciprocity using the same. In the optical fiber, the optical fiber matrix material is a ferroelectric solid state material, and the ferroelectric solid state material is doped by a rare earth element such as erbium (Er) or thulium (Tm). The optical fiber is characterized by an optical amplification function and an optical non-reciprocity function.

Abstract: A tunnel junction device capable of controlling its spin retention is provided. The tunnel junction device includes a La0.6Sr0.4MnO3-? electrode (12), a La0.6Sr0.4Mn1-yRuyO3-? electrode (14), both as ferromagnetic (including ferrimagnetic) metal materials, and a LaAlO3-? (electrically insulating layer) (13) arranged between the two electrodes (12) and (14).

Abstract: A tunnel junction device capable of controlling its spin retention is provided. The tunnel junction device includes a La0.6Sr0.4MnO3-? electrode (12), a La0.6Sr0.4Mn1-yRuyO3-? electrode (14), both as ferromagnetic (including ferrimagnetic) metal materials, and a LaAlO3-? (electrically insulating layer) (13) arranged between the two electrodes (12) and (14).

Abstract: To provide a tunnel junction device having a high MR ratio even at room temperature, a tunneling film as a nonmagnetic layer of three-layer structure of LaMnO3/SrTiO3/LaMnO3 is arranged between a ferromagnetic metal material La0.6Sr0.4MnO3 (12) and a ferromagnetic metal film material La0.6Sr0.4MnO3 (14). The tunneling film comprises two unit layers of LaMnO3 (13A) arranged on the ferromagnetic metal material La0.6Sr0.4MnO3 (12); five unit layers of SrTiO3 (13B); and two unit layers of LaMnO3 (13C) arranged at the interface between the SrTiO3 (13B) and the ferromagnetic metal film material La0.6Sr0.4MnO3 (14).

Abstract: The present invention provides a magnetic sensor capable of reproducing a magnetic record even if the size of a recorded magnetization is a minute one, directly reading a magnetization recorded on a magneto-optical disk without applying incident light itself to the magneto-optical disk, and obtaining signals of a second harmonic having a high S/N ratio. This magnetic sensor includes a magnetic sensor element (102) having electric polarization disposed with respect to a perpendicular recording medium (101), and laser generating means acting on the magnetic sensor element (102). The magnetic sensor reads information in the perpendicular recording medium (101) based on the variation of the rotation angle ? of the polarization plane of a second harmonic (105) of a frequency 2? exiting the magnetic sensor element (102) by the application of laser light (104) with a frequency ? from the laser generation means to the magnetic sensor element (102).

Abstract: Disclosed is a high-pressure generation apparatus, which comprises a pair of columnar-shaped anvils disposed in opposed relation to one another to define a pressure-generating space therebetween. The anvils are adapted to be applied with a load therebetween to generate a high pressure in the pressure-generating space. Each of the anvils has a top portion formed in an approximately circular truncated cone shape, and the top portion has a central region formed with a depression having a side surface which extends obliquely outward. The high-pressure generation apparatus also includes a cylindrical capsule disposed in a central area of the pressure-generating space, and a laminated member formed by alternately laminating a doughnut-shaped metallic thin plate and a doughnut-shaped insulating member along the outer periphery of the capsule. The improved shape of the depression makes it possible to significantly reduce damages of the components.

Abstract: A magnetooptic element whose size is essentially that of a lattice, namely several angstroms in size of magnetic material and which at the same time has its exhibiting magnetooptic effect detectable is provided along with a magnetooptic disk, a memory device and a magnetooptical picture or image display with a storage capacity of several terabits per square inch or more, each using such a magnetooptic element. The magnetooptic element utilizes a gigantic effective magnetic filed based on a spin chirality formed by geometrically configuring the spin orientation and crystallographic structure of a certain solid material.

Abstract: A manufacturing method of a Ga2-xFexO3 crystal is provided which can form a superior, uniform, and large crystal. By a floating zone melting method in which ends of material bars (3, 5), which are disposed at an upper and a lower position and which are composed of Ga2-xFexO3, are heated in a gas atmosphere with halogen lamps (6, 7) disposed at confocal areas so as to form a floating melting zone between the ends of the material bars (3, 5) which are disposed at the upper and the lower position and which are composed of Ga2-xFexO3, Ga2-xFexO3 a single crystal having an orthorhombic crystal structure is formed.

Abstract: In a photoelectric signal conversion device comprising a substrate (4), formed thereon a thin film (3) that functions as a light detection portion (5), and a pair of electrodes (2) provided thereon across the light detection portion, the thin film constituting the light detection portion is made of a solid state phase transition material and the pair of electrodes are made of a superconductive material, whereby the light detection portion can respond to optical signals on the order of psec. and the device can follow ON-OFF signals of terahertz.

Abstract: The present invention provides a magnetic sensor capable of reproducing a magnetic record even if the size of a recorded magnetization is a minute one, directly reading a magnetization recorded on a magneto-optical disk without applying incident light itself to the magneto-optical disk, and obtaining signals of a second harmonic having a high S/N ratio. This magnetic sensor includes a magnetic sensor element (102) having electric polarization disposed with respect to a perpendicular recording medium (101), and laser generating means acting on the magnetic sensor element (102). The magnetic sensor reads information in the perpendicular recording medium (101) based on the variation of the rotation angle ? of the polarization plane of a second harmonic (105) of a frequency 2? exiting the magnetic sensor element (102) by the application of laser light (104) with a frequency ? from the laser generation means to the magnetic sensor element (102).

Abstract: A manufacturing method of a Ga2-xFexO3 crystal is provided which can form a superior, uniform, and large crystal.

Abstract: A magnetooptic element whose size is essentially that of a lattice, namely several angstroms in size of magnetic material and which at the same time has its exhibiting magnetooptic effect detectable is provided along with a magnetooptic disk, a memory device and a magnetooptical picture or image display with a storage capacity of several terabits per square inch or more, each using such a magnetooptic element. The magnetooptic element utilizes a gigantic effective magnetic filed based on a spin chirality formed by geometrically configuring the spin orientation and crystallographic structure of a certain solid material.

Abstract: A magneto-resistance effect element includes an oxide substrate having on its surface steps of atomic layer level and on the substrate an epitaxially grown ferromagnetic oxide thin film, the thin film formed on the atomic layer level steps having an antiphased domain boundary.

Abstract: A manganese oxide material has MnO.sub.3 as a matrix. It is an antiferromagnetic insulator and, when subjected to an electrical current or electric field, it is transformed into a ferromagnetic metal.

Abstract: A magnetoresistor with an ordered double perovskite structure is an oxide crystal which has an ordered double perovskite crystal structure represented by the general formula of A.sub.2 BB'O.sub.6, wherein A stands for Sr atoms, B for Fe atoms and B' for Mo or Re atoms and wherein the Fe atoms and the Mo or Re atoms are alternately arranged and which exhibits negative magnetoresistive characteristics.