JPH1041124A - Superconducting device using modulation super structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a critical temperature and a critical magnetic field by producing a superconducting material obtained by introducing modulated structures and optimizing both structures, so that internal magnetic moment in a metallic super lattice is organized and the dimension of a momentum space is made to be low. SOLUTION: In a device, several types of conductors are alternately stacked. The types of the conductors (containing vacuum), the phases of the conductors and particles acting as a factor for conduction are not restricted. Layers (A layers) whose spin interactions are strong and layers (B layers) detaching them are alternately formed. For organizing internal magnetic moment and for making the dimension of momentum space to be low, the thicknesses of the A layers take disturbed values restricted by a Laue diffraction function G and a coherent distance ξ. The thicknesses of the B layers take prescribed values for optimizing the spin exchange operations between the A layers and canceling the whole number of spin quantum number. The modulated structure in the stacking direction can be introduced to a three-dimensional structure, a two-dimensional structure and one-dimensional structure. The modulated structure can be introduced to the directions of two axes and more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial applications] Energy generation, transmission, conversion,
It is expected to be applied not only to storage and other applications, but also to information communication fields such as high-speed operation devices and information medium conversion devices, or as highly efficient photon radiation sources used for measurement and evaluation. it can.

[0002]

2. Description of the Related Art K. Since the discovery of the superconducting phenomenon of Hg by Ones ¹ , metals, alloys,
By using intermetallic compounds, compounds and organic substances,
Applications to industrial applications have been attempted. But,
In order to enable advanced applications of superconductors, (1) having a high critical temperature (Tc) that does not require advanced cooling, and (2) ensuring a function in a strong magnetic field. Having a high critical magnetic field (Hc), (3) having a high critical current density (Jc) and a long coherence length (ξ) for maintaining operation when a microstructure is formed; The following three points are required. As a result of 75 years of innovation,
In 1986, oxide superconductors were introduced by J.A. A. Bednor
z, K .; A. Discovered by Muller ² ; I
demonstrated by Hara et al. With the oxide superconductor, a critical temperature of about 100K was attained, high cooling was not required, and it appeared as if the application range was expanded. However, properties such as critical magnetic field or critical current density have not yet surpassed conventional metal-based materials.
^3. Not a practical material.

[0003]

When [0006] organizing problems not solved in the oxide superconductor to date, (1) has a high critical temperature, the value ⁴ for practical use in critical magnetic field, critical current density both ( Jc = 10 ⁵ A in a magnetic field of 5T
/ Cm ² ). (2) Stability measures against quenching are difficult due to high internal resistance during normal conduction. (3) Since the coherence length in the c-axis direction is short, it is difficult to create an element using propagation in a direction perpendicular to the persistent current. Such problems are highlighted.

[0004]

Means for Solving the Problems In order to solve the problems, attention was paid to a metal superlattice. Metallic materials have high critical magnetic fields,
It has features such as critical current density, high workability, high structure reproducibility during microstructure formation, low internal resistance during normal conduction, and long coherence length. Therefore, there have been many reports on the properties of metal superlattices in the past.
^5,6,7 . However, the similarity of superconductivity and giant magnetoresistance effect, and attention to spin exchange interaction, the internal magnetic
There has been no example in which a superconducting device has been manufactured from the viewpoint of ordering the moment and reducing the dimension of the momentum space . Although both are contradictory elements, it was thought that by introducing a modulation structure (a structure having a non-integer order periodicity), it is possible to artificially create a material that optimizes both.

[0005]

According to the present invention, (1) a high critical temperature (T
c). (2) It has a high critical magnetic field (Hc) for ensuring its function in a strong magnetic field. (3) In order to maintain the operation when the fine structure is formed,
It has a high critical current density (Jc) and a long coherence length (ξ). (4) A material that does not cause quenching due to its structure can be selected. (5) Inexpensive materials can be selected. A superconducting device having the characteristics described above can be manufactured.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS No modulation structure has been introduced to date.
However, it seems possible to introduce a modulation structure into the superconductor ⁸ . The method of making this device will be described below. (1) A method for producing a layered structure by a mechanical alloying method. (2) A method of producing a layered structure by a processing method based on mechanical deformation (including a forging method, a rolling method, and the like). (3) Layered structure production method by controlling solidification structure (including rapid solidification method). (4) A layered structure manufacturing method by a thin film manufacturing method (including a physical manufacturing method and a chemical manufacturing method in a gas phase, a liquid phase, and a solid phase). (5) A method for producing a layered structure using a chemical technique. (6) A method of forming a layered structure using an electrochemical method. (7) A method for producing a layered structure using a biochemical technique. (8) A method for producing a layered structure utilizing the periodicity of a structure existing in the natural world. (9) A method for producing a layered structure using a driving force existing in the natural world. (10) A method for producing a layered structure using a physical method (such as a particle accelerator). It should be noted that a method combining a plurality of these is included.

[0007]

It is believed that a superconducting device using a modulated superstructure enables a new superconductor having a high critical temperature characteristic of an oxide superconductor without impairing the characteristics of metallic materials. Can be In addition, new devices utilizing superconductivity are considered within the scope of this device. They are not only expected to be applied to the generation, transmission, conversion, and storage of energy, but are also used in the information and communication fields such as high-speed operation elements and information medium conversion elements, or used for measurement and evaluation. The application as a highly efficient photon radiation source is expected. In addition, if these technologies are realized, computers that operate at high speed with low power consumption, high-speed and high-density information communication, high-efficiency observation and measurement, effective use of solar energy, and high-efficiency power transmission will be possible. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the present apparatus (particularly when metal is used).

FIG. 2 shows an example of a unit cell of an element to which the present apparatus is applied (particularly when a metal is used)

FIG. 3 is a cross-sectional view of the present apparatus (when a modulation structure is introduced in two or more axes).

Claims (2)

[Claims] (1) An apparatus in which several types of conductors are alternately stacked. (2) The conductor is not limited. Including vacuum. (3) The phase of the conductor is not limited. (4) The particles responsible for conduction are not limited. (5) A layer having a strong spin interaction (A layer) and a layer separating the layer (B layer) are alternately formed. The internal structure of each layer may conform to this. (6) In order to achieve both ordering of the internal magnetic moment and reduction of the dimension of the momentum space, the thickness of the A layer is a disturbed value limited by the Laue diffraction function (G) and the coherence length (ξ). The thickness of the B layer takes a constant value that optimizes the spin exchange interaction between the A layers and cancels out the total spin quantum number. As a result, it has a modulation structure in the stacking direction. (7) The modulated superstructure can be introduced into a three-dimensional structure, a two-dimensional structure, and a one-dimensional structure. (8) Includes a modified superconducting device. (9) The modulation structure can be introduced in two or more axes. 2. An apparatus to which the apparatus according to claim 1 is applied.