JPH0812483A - Horizontal apparatus for manufacturing crystal of oxide superconducting material - Google Patents

Abstract

PURPOSE:To obtain a superconducting material having a high quality crystal only in a required direction by dividing one end of a high temperature heating zone into an upper and lower heating zone, inserting a pair of cantilever heating members into each of the upper and lower heating zone from left and right hand side, making the space between each of heating members variable and realizing three-dimensional temperature gradients. CONSTITUTION:A low temperature heating zone A has an upper heating zone 2 and a lower heating zone 2a where same strengths of electrical power are each applied. A high temperature heating zone B is located on its right hand side. A high load density zone is divided in the longitudinal direction and each of the sections is provided with a bar-shaped heating member. The 3rd and the 5th heating member 6, 8 are each placed in each section of the upper heating zone and the 4th and 6th heating member 15, 17 are each placed in each section of the lower heating zone. The spaces between each heating section are made variable and each of the heating sections is independently controlled in terms of temperature. This heating system enables the homogeneous temperature distribution in the electrical furnace in X direction and the lowering of the temperature in the middle part than those of the edge parts, and realizes an ideal temperature distribution. Further, the 1st and the 2nd bar-shaped heating member generating heat of high load density 4, 12 are placed at the left end of the high temperature heating zone B and temperatures of these heating members are controlled independently from each other. The temperature gradients in Y and Z directions are produced by the move of the low temperature heating zone A on a rail 20 and the independent heating in vertical direction in the high temperature heating zone B, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an oxide superconductor crystal production apparatus for producing oxide superconductor crystals.

[0002]

2. Description of the Related Art As one of conventional devices for producing an oxide superconductor, there is a box-type electric furnace device 35 formed of a heat insulating material 35a as shown in FIG. When an oxide superconductor is manufactured by 35, the sample 36 is placed on the sample table 38 installed inside the box-type electric furnace device 35b, and the special heating element 37 is arranged in the direction perpendicular to the two surfaces of the sample 36. The inlet 40 and the gas outlet 41 are formed, and the apparatus is manufactured by a device having a structure that allows gas to flow. Reference numeral 39 is a thermocouple. In such a box-type electric furnace device 35, the maximum temperature gradient in the vertical direction and the horizontal direction of the sample 36 is 5 to 20 when the gas is flowed.
C./cm is the limit, and when manufacturing oxide superconductors using this equipment, the internal temperature is raised to 1100.degree.
It was manufactured by holding it for 0 minutes, then lowering it to 1000 ° C., and cooling it to 870 ° C. at a rate of 1 ° C./h.

The disadvantage of this box-type electric furnace device 35 is that the sample 3
When the size of 6 is changed, the obtained temperature gradient changes, and it is difficult to manufacture a high-quality, stable Jc stable oxide superconductor crystal with good reproducibility. Therefore, it is difficult to upsize the device. there were. Although there are other oxide superconductor crystal production equipment, the equipment separates the high-temperature part and the low-temperature part, and the high-temperature heating part is independent from the top and bottom. An electric furnace in which a load density type heating element is arranged, and a device for driving a sample is provided on the side of the electric furnace.By slowly moving the sample while setting it at a certain temperature, the oxide superconductor crystal can be removed. It is a synthesizer device. In such an electric furnace device as described above, a temperature gradient is provided only in the Y and Z directions, and the temperature distribution in the X direction is such that the temperature of the central portion of the furnace core tube becomes high and the end portions become low, which is originally Although it is desired to crystallize from the central part of the sample, crystallization also occurs from the end part of the sample, and there is a drawback that crystals of other orientations are mixed in addition to the crystal of the required orientation.

[0004]

SUMMARY OF THE INVENTION The present invention has been invented to solve the drawbacks of each electric furnace device described above. INDUSTRIAL APPLICABILITY The present invention is particularly used in a field in which an object to be heated needs to be processed in a special temperature gradient in three directions of X (horizontal direction), Y (horizontal direction) and Z (vertical direction) due to physical properties. In addition to being a device capable of producing a set temperature of a plurality of heating sections from a sudden temperature gradient to a certain arbitrary temperature gradient in the X, Y, and Z directions, it is a device with a three-dimensional free temperature distribution, and an oxide. Other than the production of superconductors, oxide superconductor crystals that can produce anisotropic oxide materials, intermetallic compounds, etc. and materials with complex components that require concentration distribution of the components inside the materials It is intended to provide a manufacturing apparatus.

[0005]

In order to solve the problems, the present invention is directed to an oxide superconductor crystal manufacturing apparatus for manufacturing oxide superconductor crystals in a horizontal direction, wherein heating parts are respectively provided in the longitudinal direction and in the vertical direction. It has divided heating parts, each heating part can be temperature controlled independently, and one or more cantilever type high load density type heating elements can be inserted from the left and right sides above and below one end of the high temperature heating part, and horizontal The horizontal oxide superconductor crystal manufacturing apparatus has a structure capable of forming temperature gradients in three directions, ie, the vertical direction, the vertical direction, and the horizontal direction.

[0006]

EXAMPLE FIG. 1 is a cross-sectional view of an electric furnace section of a horizontal oxide superconductor crystal manufacturing apparatus according to the present invention. This apparatus has a low temperature heating section A (heating element is Kanthal A-1) on the left side. The low temperature heating unit A has an upper heating unit 2 and a lower heating unit 2a, which are separate heating units.
Also, the same electric power is supplied to the lower heating unit 2a. Reference numeral 1 indicates a fiber-molding type heat insulating material, and reference numeral 3 indicates a control thermocouple for a low temperature electric furnace.

On the other hand, a high temperature heating section B is arranged on the right side, and four cantilevered heating elements (two heating elements in upper and lower portions) (SiC is a heating element) are provided in the high-load dense portion, and each pair is temperature controlled. Further, on the right side thereof, a rod-shaped heating element (heating element is SiC) is arranged vertically to control the temperature. That is, the upper high temperature heating part is the third heating element 6 (the heating element is Kanthal A-
1) and the fifth heating element 8 (heating element is Kanthal A-1), and the lower high-temperature heating section is the fourth heating element 15 (heating element is Kanthal A-1) and the sixth heating element 17 (heating element). Is Kanthal A-
It is composed of 1). Reference numeral 7 is a third heating body control thermocouple, reference numeral 9 is a fifth heating body control thermocouple, reference numeral 14 is a fourth heating body control thermocouple, and reference numeral 16 is a sixth heating body control thermocouple. Shows a pair.

Further, at the left end of the high temperature heating section B, a rod-shaped first heating element high load density heating element 4 and a second heating element high load density heating element 12 (each heating element is SiC) are arranged vertically. By the feedback of the first heating body controlling thermocouple 5 and the second heating body controlling thermocouple 13, the temperature can be controlled independently. The upper first heating element high-load density heating element 4 is a first heating element (high-load density heating element SiC), and the lower high-load density heating element 12 is a second heating element (high-load density heating element SiC).

The low temperature heating section A is movable on a moving rail 20 by a moving vehicle 18. Reference numeral 19 is a height adjusting column for adjusting the height. The high temperature heating part B is supported by a column. The distance between the left and right heating units, that is, the distance between the low-temperature heating unit A and the high-temperature heating unit B can be changed by the moving vehicle 18 attached to the lower portion of the low-temperature heating unit A.

FIG. 2 is a vertical sectional view taken along the line AB in FIG. That is, it is a vertical cross-sectional view of the high temperature heating part B of the oxide superconductor crystal manufacturing apparatus of the present invention. As shown in FIG. 2, a transparent quartz square furnace core tube 10 is arranged inside the furnace. Inside the transparent quartz square furnace core tube 10, two quartz trays are provided on the lower left and right sides. There is a rail 11.11a, and the sample 22 placed on the sample table 23 can be moved by the drive rod 21 on the transparent quartz rail 11.11a. Inside the transparent quartz square furnace core tube 10, a sample table 23
Has a hole at two places at the right end thereof, and the protrusion 21a at the tip of the quartz drive shaft is inserted into the hole and fixed, and the drive base holding the drive shaft is driven.

FIG. 3 is a view showing a sample moving mechanism of the oxide superconductor crystal manufacturing apparatus according to the present invention. This sample moving machine C is a heating unit main body composed of a low temperature heating unit A and a high temperature heating unit B. It will be installed on the right side. The projection 21a to be inserted into the sample table 23 has the transparent quartz sample drive rod 21 formed at the tip thereof with the height adjusting screw 26 and the drive rod fixing screw 27.
It is fixed to the drive mechanism rail 24 via the
The sample driving rod 21 made of quartz is driven by the driving of the drive mechanism 28 such as a motor and a gear arranged inside the table 30 for the sample, and the sample table 23 is pushed or pulled to thereby obtain the sample 2
2 can be moved left and right at high speed or low speed. The sample (oxide superconductor) 22 placed on the sample table 23 is crystallized by moving at a speed of 2 mm / h in the temperature gradient of this device. Reference numeral 25 is a moving base, reference numeral 26 is a height adjusting screw, reference numeral 29 is a ball screw portion, reference numeral 30 is a rail stand, reference numeral 31 is a drive mechanism base, reference numeral 32 is a mount, and reference numeral 33.
Is a timing belt, and reference numeral 34 is a timing pulley.

FIG. 4 is a cross-sectional view and a temperature distribution diagram of a steep temperature gradient portion of the oxide superconductor crystal manufacturing apparatus according to the present invention. That is, using the oxide superconductor crystal manufacturing apparatus of the present invention, the temperature of the low temperature heating part A is set to 600 ° C., the first heating body 4 of the high temperature heating part B is 1200 ° C., and the second heating body 1 is
2 is 1090 ° C., the third heating body 6 is 1200 ° C., the fourth heating body 15 is 1128 ° C., the fifth heating body 8 is 1200 ° C., the sixth
It shows the temperature distribution in the longitudinal direction when the heating element 17 is set to 1150 ° C. As is clear from this temperature distribution diagram, in the conventional device, the temperature at the center position of the vertical section becomes high. For this reason, subgrain crystals are generated at the low temperature portions at both ends of the sample. In the oxide superconductor crystal manufacturing apparatus of the present invention, the drawbacks of the conventional apparatus as described above can be solved, and the temperature at the center position can be lowered. Therefore, the sub-grains from both ends can be reduced. It became possible to suppress the formation of crystals.

In this embodiment, the high temperature heating section B and the low temperature heating section A are air-cooled, but if the descending parts for gas cooling and water cooling are forcibly inserted between them, the cooling effect is improved. It is possible to obtain a larger temperature gradient. In addition, the heating element of the high temperature heating unit 4, 6, 8, 12,
It is also possible to change 15 and 17 from SiC to LaCrO type or MoSi type.

In the present invention, the upper and lower portions of one end of the high temperature heating section B are separated, and one to two cantilevered heating bodies are inserted into each of the left and right sides so that the distance can be changed. The temperature distribution in the direction can be made uniform, and the temperature distribution in the central portion can be lowered to an ideal distribution.

This makes it possible to provide a lateral oxide superconductor crystal manufacturing apparatus which can obtain an ideal temperature distribution in the X, Y and Z directions. This state can be seen from the structure in which a horizontal sectional view of the present apparatus is shown in FIG. 1 and a vertical sectional view of a portion where the upper and lower parts of one end of the high temperature heating portion B are separated from each other is shown in FIG.

In the structure of the lateral oxide superconductor crystal manufacturing apparatus according to the present invention, the temperature gradient in the Y direction is obtained by separating the low temperature heating section A and the high temperature heating B and changing the distance between them. The temperature gradient is obtained by making the upper and lower directions of the high temperature heating section B independent, and the temperature gradient in the X direction is such that the heating elements of the high temperature heating section B are arranged in separate cantilevered heating elements from the left and right,
The temperature of the central portion is low not only in the Y and Z directions but also in the X direction in the crystallized portion by controlling the temperature setting of the independent heating bodies independently with a constant relationship with the structure that can change the interval. It is possible to obtain an ideal temperature distribution.

The maximum temperature gradient obtained by the present horizontal oxide superconductor crystal manufacturing apparatus is 80 ° C./maximum temperature gradient in the Y direction.
cm, 50 ° C./cm in the Z direction, and ± 3 ° C./cm from the outside to the center in the X direction. When manufacturing a high-quality oxide superconductor, the temperature gradients in these three directions are effective.

The sample 22 is placed on the sample table 23 in the temperature gradient of the present horizontal oxide superconductor crystal manufacturing apparatus, and each heating unit A
The oxide superconductor crystal can be synthesized by setting the temperature of B to a predetermined temperature, increasing the temperature, maintaining the temperature at a constant temperature, and then decreasing the temperature at a slow rate.

Next, a sample driving mechanism C is arranged on the lateral side of the present horizontal oxide superconductor crystal manufacturing apparatus (see FIG. 4),
In the temperature gradient obtained in this manufacturing apparatus, the sample table 23 is moved to 2 m.
By moving at a low speed such as m / h, it is possible to manufacture a high-quality, large-sized and long oxide superconductor crystal having two phases of a superconducting phase and a non-superconducting phase.

In addition, in the method for producing a high-performance oxide superconductor crystal, the transparent quartz square furnace core tube 10 is controlled so that the atmosphere during growth can be controlled to an oxygen concentration suitable for the material to be synthesized. Both ends have a seal structure so that a vacuum can be drawn and nitrogen gas and oxygen gas can flow. That is, FIG.
As shown in FIG. 2, seal flanges 10a and 10c are provided at both ends to form a seal structure by O-rings 10b and 10d.

[0021]

Since the present invention has the configuration described above, the following effects can be obtained. First, by inserting cantilevered heating elements into the high-density temperature section separately on the right and left sides, and changing the intervals, an electric furnace having temperature distribution in the longitudinal direction, the vertical direction, and the X direction can be manufactured, and the maximum temperature gradient is obtained. Is 80 ° C in the Y direction
It was possible to obtain 40 ° C./cm in the cm and Z directions and 3 ° C./cm in the X direction. Secondly, it is a universal electric furnace that can obtain a temperature distribution in three directions of 0 to 80 ° C./cm by arbitrarily changing the set temperature of each heating section, depending on the composition of various oxide superconductors. By selecting an appropriate temperature and temperature gradient obtained from this apparatus, it is possible to obtain the effect that a high-quality oxide superconductor crystal can be manufactured. Third, using the present invention, the superconducting oxide YBaC
When uO is manufactured, a two-phase crystal can be stably manufactured, and a rectangular parallelepiped crystal having a size of 40 W × 20 H × 40 L mm can be obtained. If the apparatus is further enlarged, a larger crystal can be continuously formed. The effect of being able to obtain it is obtained. Fourthly, in manufacturing a product to which the superconducting phenomenon is applied, there is an effect that a large amount of a stable superconducting oxide having high characteristics can be obtained quickly, inexpensively and with high characteristics. Fifth, it is possible to produce an oxide superconductor having a free shape to some extent, for example, a rectangular shape, a circular shape, a ring shape, and the like, and to produce a long oxide superconductor crystal. can get. Sixthly, an effect is obtained that seeding can be carried out and the present invention can be applied to the case of producing a crystal body containing a different phase and anisotropy other than the oxide superconductor.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an electric furnace portion of an oxide superconductor crystal manufacturing apparatus according to the present invention.

FIG. 2 is a vertical cross-sectional view of a high temperature heating unit of the oxide superconductor crystal manufacturing apparatus according to the present invention.

FIG. 3 is a movement mechanism diagram of an oxide superconductor crystal manufacturing apparatus according to the present invention.

FIG. 4 is a cross-sectional view and a temperature distribution diagram of a steep temperature gradient portion of the oxide superconductor crystal manufacturing apparatus according to the present invention.

FIG. 5 is a vertical sectional view of a furnace portion of a known oxide superconductor crystal manufacturing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fiber-molding type heat insulating material 2 Low temperature electric furnace part 3 Low temperature electric furnace control thermocouple 4 1st heating body (high load density heating element SiC) 5 1st heating body control thermocouple 6 3rd heating body (Kantal A- 1) 7 3rd heating body control thermocouple 8 5th heating body control (kanthal A-1) 9 5th heating body control thermocouple 10 Transparent quartz square furnace core tube 10a Seal flange 10b O-ring 10c Seal flange 10d O Ring 11 Quartz rail 12 Second heating element (high load density heating element SiC) 13 Second heating element control thermocouple 14 Fourth heating element control thermocouple 15 Fourth heating element (Kanthal A-1) 16 6th heating system control thermocouple 17 6th heating element (kanthal A-1) 18 Moving car 19 Height adjusting support column 20 Moving rail 21 Quartz sample drive rod 22 Sample (oxide superconductor) 23 Sample table 2 Drive mechanism rail 25 Moving base 26 Height adjusting screw 27 Drive rod fixing screw 28 Motor / gear etc. drive mechanism part 29 Ball screw part 30 Rail base 31 Drive mechanism base 32 Frame 33 Timing Belt 34 Timing pulley 35 Box-type electric furnace device 35a Heat insulating material 35b Box-type electric furnace device 36 Sample 37 Heating element 38 Sample stage 39 Thermocouple 40 Gas inlet 41 Gas outlet

Claims (3)

[Claims] 1. An oxide superconductor crystal production apparatus for producing an oxide superconductor crystal in a horizontal direction, wherein the heating section has heating sections divided in a longitudinal direction and a vertical direction, respectively.
The temperature of each heating part can be controlled independently, and one or more cantilever type high load density type heating elements can be inserted from the left and right above and below one end of the high temperature heating part. Horizontal oxide superconductor crystal manufacturing equipment that can take temperature gradients in three directions. 2. The apparatus for producing a horizontal oxide superconductor crystal according to claim 1, further comprising a moving mechanism capable of moving the sample at the entrance and exit of the transparent quartz furnace core tube. 3. The horizontal oxide superconductor crystal according to claim 1, wherein the inlet and outlet of the transparent quartz furnace core tube have a seal structure and a structure capable of evacuating and replacing gas. Manufacturing equipment.