CN116254604A - A method of melt-textured growth of GdBCO superconducting bulk prepared by combining top seed and inner seed - Google Patents

Abstract

The invention provides a method for preparing a GdBCO superconducting bulk material by combining a top seed crystal and an internal seed crystal. The method comprises the following steps: firstly, preparing seed crystals, a transmission layer, a solid phase precursor block, a liquid phase precursor block and a supporting block, wherein the seed crystals are arranged in the precursor block; and then assembling the blank, and after the assembly is completed, adopting a fused texture growth method to simultaneously induce and grow the GdBCO texture block by using the top seed crystal and the internal seed crystal. The preparation method provided by the invention further shortens the preparation time of the large-size texture GdBCO superconducting bulk material, and improves the mechanical strength, the superconducting performance and the uniformity of the large-size sample.

Description

A fusion-woven method for the preparation of GdBCO superconducting bulk by combining top seed and inner seed structure growth method

technical field

The invention belongs to the technical field of high-temperature copper oxide superconducting materials, and in particular relates to a method for growing a melting texture of a GdBCO superconducting bulk material by combining a top seed crystal and an internal seed crystal.

Background technique

The preparation of large-size superconducting bulk materials with multi-seed crystals has its advantages, such as shortening the sample preparation period, reducing the preparation cost and good superconducting properties of the samples. REBCO superconductor is famous for its high critical temperature, large unimpeded current carrying capacity, high capture magnetic field and large magnetic levitation force, so it is used in high magnetic field permanent magnets, superconducting magnetic bearings, superconducting energy storage flywheels, motors , generators and magnetic levitation systems have been widely used, so there is a greater demand for large-size superconducting bulk materials.

However, the long growth time of large-sized superconducting bulk materials will lead to particle coarsening, which seriously affects the performance of superconducting bulk materials. In the traditional method, multiple seed crystals on the surface are simultaneously induced to grow, but the weak links formed by the grain boundaries seriously affect the performance of superconducting bulk materials. In order to improve weak links, various methods have been proposed. For example: changing the seed angle; placing a transition layer under multiple seeds; changing the composition of weak links, etc.

There are many uncontrollable factors in the existing technology. For example: by changing the angle of the seed crystal, since the seed crystal tends to drift during the heat treatment process, it is difficult to keep it at an angle precisely. In the method of placing the transition layer, since the growth rate of the a/c plane is different, the subdomain area generated is larger, so a thicker transition layer is required, and an excessively thick transition layer will make the growth time longer and make the particles coarser. , affecting its performance. Another method is to improve the components at weak links. This method is not easy to promote because the components and their regions are uncontrollable. At the same time, these methods are not conducive to the preparation of large-sized GdBCO superconducting bulk materials with high mechanical strength, good superconducting properties and good uniformity.

Single-seed crystal: the prepared single-domain GdBCO superconducting bulk material, the larger the sample, the farther away from the seed crystal, the greater the orientation of the induced growth REBCO grain deviates from the seed crystal orientation, and the uniformity of the sample decreases, resulting in a large size The performance of the samples are far inferior to the small size samples.

Multi-seed crystals: In order to overcome the shortcomings of single-seed crystals in the preparation of large-scale single-domain REBCO superconducting bulk samples, people hope to use the top multi-seed crystal method to prepare large-scale samples, but the large-scale REBCO superconducting bulk materials prepared by this method For the sample, since the single-domain GdBCO superconducting bulk materials induced by each seed crystal are in planar contact, there are problems of low mechanical strength, low superconducting performance, and poor uniformity for the entire sample.

These problems cannot be solved by the current existing methods, so we invented this new method, which can be used to prepare large-size GdBCO superconducting bulk materials with high mechanical strength, good superconducting performance and uniformity.

Contents of the invention

The purpose of the present invention is to provide a method for the fusion texture growth of a GdBCO superconducting block prepared by combining the top seed crystal and the internal seed crystal. By setting the seed crystal inside the precursor block, the addition of the internal seed crystal effectively improves the grain The shape improves the superconducting properties of the sample.

In order to achieve the above-mentioned purpose, the present invention provides a method for the fusion texture growth of a top seed crystal combined with an internal seed crystal to prepare a GdBCO superconducting bulk material, comprising the following steps:

S1: Preparation of neodymium barium copper oxide seed crystal;

S2: Preparation of precursor powder

Mix Gd ₂ O ₃ , BaCO ₃ and CuO in a molar ratio of 1:1:1, and make Gd211 by solid-state sintering; mix Gd ₂ O ₃ , BaCO ₃ and CuO in a molar ratio of 1:4:6, and use solid Prepare Gd123 by phase sintering method; mix Gd123: Gd211 at a ratio of 1:0.4mol, then add 1wt% CeO ₂ and mix evenly, as a precursor powder;

S3: Suppression of Herald Blocks

Take the precursor powder and NdBCO seed crystal, put the precursor powder into the mold in batches, and place the seed crystal on the upper surface of each layer of precursor powder in batches, and then put the remaining precursor powder into the mold Inside the mold, finally, pressed into the precursor block;

S4: Press Y ₂ O ₃ support block with Y ₂ O ₃ powder;

S5: Assembly blank

Take 1 Al ₂ O ₃ spacer, 1 Y ₂ O ₃ support block, 1 pioneer block, several MgO single crystal blocks, and several neodymium barium copper oxide seeds;

Assembled in an axisymmetric manner, several MgO single crystal blocks were placed on top of the Al ₂ O ₃ gasket, Y ₂ O ₃ support blocks were placed on top of the MgO single crystal blocks, pioneer blocks were placed on top of the Y ₂ O ₃ support blocks, and several Neodymium-barium-copper-oxide seed crystals are placed on top of the pioneer block;

S6: preparing the green body into a textured gadolinium barium copper oxide bulk material by a melt texture growth method;

S7: Oxygen permeation treatment

Put the gadolinium-barium-copper-oxygen block into the oxygen infiltration furnace, heat it rapidly to 430°C, pass it into the oxygen infiltration furnace at a flow rate of 200ml/min of oxygen, cool down slowly to 350°C after 200 hours, and then cool to room temperature with the furnace. A gadolinium-barium-copper-oxygen superconducting bulk material is obtained.

Further, step S1 specifically includes the following steps:

Mix Nd ₂ O ₃ , BaCO ₃ , and CuO powders at a molar ratio of 1:1:1 to make Nd ₂ BaCuO ₅ by solid state sintering; then mix Nd ₂ O ₃ with BaCO ₃ , CuO The volume molar ratio _is 1 _: 4:6 and mixed evenly, and _{NdBa 2} Cu ₃ O _{7 -δ} is produced _by solid state sintering method; : 3 mixed uniformly, pressed into NdBCO precursor blocks, sintered in a crystal growth furnace with the top seed melting texture method, to obtain NdBCO block materials; seed crystal;

In the above formula, 0≤δ≤1.

Further, step S6 specifically includes the following steps:

Put the assembled green body into the crystal growth furnace, first raise the temperature to 900°C at a heating rate of 80-120°C/h, and keep it for 10 hours; ~2 hours, then cool the temperature to below 1040°C at a rate of 60-100°C/h, then lower the temperature to 1020°C at a rate of 0.2-1°C/h, and cool naturally to room temperature with the furnace to obtain the top seed crystal Textured gadolinium-barium-copper-oxygen bulks combined with inner seeds to induce growth.

Further, step S8 specifically includes the following steps: placing the textured gadolinium-barium-copper-oxygen bulk material induced by the combination of the top seed crystal and the internal seed crystal into a quartz tube furnace; Heating in the zone for 200 hours, the textured gadolinium-barium-copper-oxygen superconducting bulk material in which the top seed crystal and the inner seed crystal were combined and induced to grow was obtained.

Further, in step S3, the precursor block is divided into k layers, k ≥ 2, the value of k is determined by the thickness (c-axis direction) of the growth of gadolinium barium copper oxide grains, and the growth of GdBCO superconducting bulk c The average growth rate of the shaft is 0.2mm/h; from top to bottom, the number of seed crystals placed on odd layers is m×n, and the number of seed crystals placed on even layers is i×j, m≥1 , n≥1, i≥1, j≥1 specific parameters can be set according to needs; the number of seed crystals placed in the same layer is determined by the diameter of the sample and the growth rate of the a-axis of the sample, m, n, i, j The specific parameters can also be set according to the needs of the situation; the average growth rate of the a-axis of the neodymium barium copper oxide seed crystal induced growth GdBCO superconducting bulk material is 0.35mm/h.

Further, the minimum distance d between adjacent seed crystals in the same layer in the precursor block is greater than or equal to 2mm; and the grain orientation of each seed crystal in the same layer is consistent, and the ab plane of the seed crystal is parallel to the upper surface of the precursor block; the seed crystal The maximum distance d between them needs to meet the requirement that the single-domain gadolinium-barium-copper-oxide grains induced by each layer of seed crystals are close to the maximum, and the grains are large enough to make the grain boundary interface area as large as possible.

Further, the orientations of the seed crystals between adjacent layers in the precursor block are consistent, the ab plane of the seed crystal is parallel to the upper surface of the precursor block, and the sum of the thicknesses of the gadolinium-barium-copper-oxygen blocks induced by each layer of seed crystal growth is greater than equal to the thickness of the precursor block.

Further, each seed crystal in the precursor block induces a single gadolinium barium copper oxide grain to grow in the same orientation, and finally, the entire sample is composed of multiple monodomain gadolinium barium copper oxide grains with the same grain orientation.

The advantages of the present invention are: the present invention provides a method for the fusion texture growth of a GdBCO superconducting block prepared by combining top seed crystals and internal seed crystals, using multiple seed crystals to simultaneously induce the growth of large-sized superconducting bulk materials, and the seeds The crystal is buried inside the precursor block, and the upper and lower ab surfaces of the inner seed crystal can induce the growth of the superconducting bulk, which increases the growth rate of the sample and improves the superconducting performance of the GdBCO superconducting bulk, and the layers are interlaced, The mechanical strength of the superconducting bulk material is improved.

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

Description of drawings

Figure 1 is a schematic diagram of the assembly of Embodiment 1.

Figure 2 is a schematic diagram of the assembly of Embodiment 2.

Figure 3 is a schematic diagram of the assembly of Embodiment 3.

Fig. 4 is a topography diagram of the large-scale textured gadolinium-barium-copper-oxide superconducting bulk grown from the top four seed crystals induced superconducting bulk in Example 1.

Fig. 5 is a diagram of the magnetic levitation force and the trapping magnetic field distribution diagram of the superconducting bulk material in Example 1.

Fig. 6 is a topography diagram of the large-scale textured gadolinium-barium-copper-oxygen superconducting bulk grown from the top five seed crystals induced superconducting bulk in Example 2.

Fig. 7 is a diagram of the magnetic levitation force and the trapping magnetic field distribution diagram of the superconducting bulk material in Example 2.

Fig. 8 is a topography diagram of a large-scale textured gadolinium-barium-copper-oxygen superconducting bulk material induced and grown by combination of four seeds on the top and one seed on the inside in Example 3.

Fig. 9 is a diagram of the magnetic levitation force and a trapping magnetic field distribution diagram of the superconducting bulk material in Example 2.

Fig. 10 is a schematic diagram of the NdBCO seed crystal in the coordinate axis.

Fig. 11 Schematic diagram of the arrangement of NdBCO seed crystals in the precursor block.

Explanation of reference numerals: 1. Neodymium barium copper oxide seed crystal; 2. Pioneer block; 3. Support block; 4. MgO single crystal block; 5. Al ₂ O ₃ gasket.

Detailed ways

In order to further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific implementation, structural features and effects of the present invention will be described in detail below in conjunction with the accompanying drawings and examples.

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In describing the present invention, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", " The orientation or positional relationship indicated by "alignment", "overlap", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than Nothing indicating or implying that a referenced device or element must have a particular orientation, be constructed, and operate in a particular orientation should therefore not be construed as limiting the invention.

The terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of these features; in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

Example 1

This embodiment provides a method for preparing a large-scale textured gadolinium-barium-copper-oxide superconducting bulk by the top multi-seed fusion growth method, which includes the following steps:

S1: Preparation of neodymium barium copper oxide seed crystal 1

Mix Nd ₂ O ₃ , BaCO ₃ , and CuO powders at a molar ratio of 1:1:1 to make Nd ₂ BaCuO ₅ by solid state sintering; then mix Nd ₂ O ₃ with BaCO ₃ , CuO The volume molar ratio _is 1 _: 4:6 and mixed evenly, and _{NdBa 2} Cu ₃ O _{7 -δ} is produced _by solid state sintering method; : 3 mixed uniformly, pressed into NdBCO precursor blocks, sintered in a crystal growth furnace with the top seed melting texture method (using magnesium oxide single crystals as seed crystals here), to obtain NdBCO blocks; Naturally cleaved neodymium-barium-copper-oxygen cubes are used as seed crystals. Specifically, the dimensions of the neodymium-barium-copper-oxide cubes are 2mm×2mm×2mm in length×width×height;

In the above formula, 0≤δ≤1;

S2: Preparation of precursor powder

S201, Preparation of GdBa ₂ Cu ₃ O _7-x (Gd123) Weigh 72.50g, 157.86g, and 95.45g of powders with Gd ₂ O ₃ : BaCO ₃ : CuO in a molar ratio of 1:4:6, respectively, and use a planetary ball mill to Mix evenly, and use the solid-state sintering method to sinter three times at 920°C to produce GdBa ₂ Cu ₃ O _7-x , where 0≤x≤1;

Preparation of S202 and Gd ₂ BaCuO ₅ (Gd211): Weigh 213.11g, 116.01g, and 46.76g of Gd ₂ O ₃ : BaCO3: CuO in a molar ratio of 1:1:1, mix them uniformly with a planetary ball mill, and use a solid phase The sintering method is sintered three times at 920°C to make Gd211;

S203. Weighing 305.08 g of Gd123 and 100 g of Gd211 in a ratio of 1:0.4 mol of Gd123:Gd211, and then adding 1 wt % CeO ₂ , that is, 4.05 g of CeO ₂ . The three powders are mixed uniformly and used as the precursor powder of the fusion growth method.

S3: Suppression Herald Block 2

Take 160g of pioneer powder and put it into a mold, and press it into a pioneer block 2 with a diameter of 50mm;

S4: Take 8g of Y ₂ O ₃ powder and press it into a support block with a diameter of 50mm;

S5: Assembly blank

Take 1 Al ₂ O ₃ spacer 5, 1 Y ₂ O ₃ support block 3, 1 pioneer block 2, several MgO single crystal blocks 4, and several neodymium barium copper oxide seed crystals 1;

Assembled in an axisymmetric manner, as shown in Figure 1, _a number of MgO single crystal blocks 4 are placed above the _Al2O3 gasket 5, _Y2O3 support blocks ₃ are placed above the MgO single crystal block 4, and the pioneer block 2 placed on _{the Y2O3} supporting block 3, and several neodymium barium copper oxide seed crystals 1 are placed on the pioneer block 2;

S6: Preparation of green body into textured gadolinium barium copper oxide superconducting bulk material by fusion growth method

Put the assembled green body into the crystal growth furnace, first raise the temperature to 900°C at a heating rate of 80-120°C/h, and keep it for 10 hours; ~2 hours, then cool the temperature to below 1040°C at a rate of 60-100°C/h, then lower the temperature to 1020°C at a rate of 0.2-1°C/h, and naturally cool to room temperature with the furnace to obtain gadolinium barium copper Oxygen block;

S7: Oxygen permeation treatment

Put the gadolinium-barium-copper-oxygen block into a quartz tube oxygen infiltration furnace, heat it up to 430°C quickly, pass it into the oxygen infiltration furnace at a flow rate of 200ml/min of oxygen, cool down slowly to 350°C after 200 hours, and then cool with the furnace to room temperature to obtain a gadolinium-barium-copper-oxygen superconducting bulk material.

Further, in this embodiment, k=1, m=4, n=1, the number of NdBCO seed crystals 1 described in step S5 is 4, and the four NdBCO seed crystals 1 are synthesized A square, the distance between the neodymium barium copper oxide seed crystals 1 on adjacent corners of the square is 20 mm.

Further, the number of MgO single crystal blocks 4 in step S5 is six.

In this example, the sample diagram of the four-seed crystal was grown, as shown in Figure 4, Figure 4 (a) is the surface topography of the four-seed crystal sample after growth, Figure 4 (b) (c) is the bulk material from <010 The side views observed in the > and <110> directions, <010> and <110> represent the crystal orientation index of the crystal. It can be seen from the figure that there is a clear cross pattern centered on each seed crystal, and each seed crystal Four growth sectors are induced, and the boundary of each sector is clearly visible, the crystal texture extends to the edge of the entire sample, and there is no spontaneous nucleation around it.

The superconducting properties of the four-seed sample superconducting precursor block after oxygen infiltration are shown in Figure 5 below. Figure 5(a) is a diagram of the magnetic levitation force measured by a permanent magnet with a diameter of 40mm and a surface magnetic field of 0.5T. It can be seen from the figure that the magnetic levitation force of the four-seed crystal sample is 94N; Figure 5(b) is magnetized at 0.5T The final trapping magnetic field distribution diagram, we can see from the figure that the peak of the sample trapping magnetic field is consistent with the number of seed crystals of the sample, and the trapping magnetic field drops obviously at the growth domain boundary of the sample.

In summary, the superconducting properties of large-size samples can be improved by using multiple seeds on the top. Four seeds can induce the growth of a large-size sample at the same time. This method greatly shortens the preparation time of large-size superconducting blocks and improves the The superconducting properties of the samples.

Example 2

The difference between this embodiment and Embodiment 1 lies in step S5.

The difference between step S5 and embodiment 1 is that in this embodiment, k=1, m=5, n=1, five neodymium barium copper oxide seed crystals are placed above the precursor block 2, and the ab planes of the seed crystals are parallel to the precursor On the upper surface of the block, one of the seed crystals is placed in the center of the upper surface of the pioneer block, and the other four seed crystals form a square. Specifically, the distance between the seeds on adjacent corners of the square is 20 mm, and the first A placed seed in the center of the square;

The other steps are the same as those in Example 1, as shown in Figure 2 below, which is the situation of the five-seed crystal induced growth superconducting precursor block. Figure 2a shows the assembly diagram of five-seed induced superconducting precursor growth.

The growth of superconducting precursor bulk induced by five-seed crystals is shown in Fig. 6. Fig. 6(a) is the surface topography of four-seed crystal sample after growth. Fig. 6(b)(c) is the bulk material from <010 The side views observed in the > and <110> directions, <010> and <110> are the crystal orientation indices. Figure 7(a) is a diagram of the magnetic levitation force measured by a permanent magnet with a diameter of 40mm and a surface magnetic field of 0.5T. It can be seen from the figure that the magnetic levitation force of the four-seed crystal sample is 89N; Figure 7(b) is magnetized at 0.5T The final trapping magnetic field distribution diagram, we can see from the figure that the peak of the sample trapping magnetic field is consistent with the number of seed crystals of the sample, and the trapping magnetic field drops obviously at the growth domain boundary of the sample.

Example 3

This embodiment provides a method for inducing the fusion growth of a GdBCO superconducting bulk material by combining top seed crystals and internal seed crystals. The difference between this embodiment and Embodiment 1 lies in steps S3 and S5.

Step S3 specifically includes the following steps:

Weigh 80g of the pioneer powder and put it into a cylindrical abrasive tool with a diameter of 50mm, and gently tilt it to keep the upper surface of the precursor powder level, as shown in Figure 10, and then place an ab on both sides at the center of the circle Neodymium barium copper oxide seed crystal 1 with better plane orientation, and make its ab plane parallel to the surface of the precursor powder, then weigh 80g of the precursor powder and continue to put it into the cylindrical abrasive tool, in order to prevent the center seed crystal from shifting , lightly level the precursor powder, and then press together to form the precursor block 2, so that we can ensure that the inner seed crystal is in the exact center of the precursor block 2.

Step S5 specifically includes the following steps:

The difference between step S5 and embodiment 1 is that in this embodiment, k=2, m=4, n=1, i=1, j=1, above the precursor block 2 are four neodymium barium copper oxide seed crystals 1, The ab planes of the NdBCO seed crystals are parallel to the upper surface of the pioneer block 2, and the four NdBCO seed crystals 1 form a square, and the NdBCO seed crystals 1 on the adjacent top corners of the square The distance is 20mm, and the internal seed crystal is placed in the center of the pioneer block 2.

As shown in Figure 8, Figure 8(a) is the surface topography of the four-seed sample after growth, and Figure 8(b)(c) is the side view of the bulk material observed from the <010> and <110> directions, There is a clear cross pattern at the center of each seed crystal on the top, four growth sectors induced by each seed crystal, and the boundaries of each sector are clearly visible, the crystal texture extends to the edge of the entire sample, and there is no spontaneous At the same time, it is obvious that there is a square area in the center of the upper surface of the sample. This area is formed by the induction of the internal seed crystal, corresponding to the c-axis growth area induced by the internal seed crystal.

The superconducting performance of the sample after oxygen infiltration is shown in Figure 9 below. Figure 9(a) is a diagram of the magnetic levitation force measured by a permanent magnet with a diameter of 40mm and a surface magnetic field of 0.5T. It can be seen from the figure that the magnetic levitation of the four-seed sample The force is 108N; Figure 9(b) is the distribution diagram of the capture magnetic field after magnetization of 0.5T, the peak of the sample capture magnetic field is consistent with the number of seeds in the sample, and the maximum value of the capture magnetic field is the largest among the three examples Yes, it reached 0.265T.

In addition, the number and arrangement of NdBCO seed crystals 1 can be designed according to the number of layers and arrangement as required, as shown in Figure 11, for example, it can be layered in the form of body-centered cubic and face-centered cubic.

In summary, the present invention induces the melting growth of GdBCO superconducting block through the combination of the top seed crystal and the internal seed crystal, and utilizes multiple seed crystals to induce the growth of large-sized superconducting block at the same time, and both sides of the internal seed crystal can be induced The growth rate of superconducting bulk material is fast; the grain interface between grains is optimized, and the superconducting performance of GdBCO superconducting bulk material is further optimized, which can reduce the mechanical strength of superconducting bulk material; at the same time, it can be used to grow larger size superconducting blocks. This method is applicable to the growth of all REBCO superconducting bulk materials (RE is a rare earth element, such as Y, Er, Ho, Sm, etc.).

The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be assumed that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the concept of the present invention, some simple deduction or replacement can be made, which should be regarded as belonging to the protection scope of the present invention.

Claims (8)

1. A method for preparing the fused texture growth of GdBCO superconducting bulk by combining a top seed crystal and an internal seed crystal, which is characterized in that: the method comprises the following steps:

s1: preparing a neodymium barium copper oxygen seed crystal (1);

s2: preparation of precursor powder

Gd is put into ₂ O ₃ 、BaCO ₃ The molar ratio of the catalyst to CuO is 1:1:1, preparing Gd211 by a solid phase sintering method; gd is put into ₂ O ₃ 、BaCO ₃ The molar ratio of the catalyst to CuO is 1:4:6, mixing, and preparing Gd123 by a solid phase sintering method; gd123: gd211 is mixed according to the proportion of 1:0.4mol, and then 1wt percent of CeO is added ₂ Uniformly mixing to obtain precursor powder;

s3: pressing precursor blocks

Taking precursor powder and neodymium barium copper oxygen seed crystal (1), putting the precursor powder into a mould in batches, simultaneously putting the seed crystal (1) on the upper surface of each layer of precursor powder in batches, then putting the rest precursor powder into the mould, and finally pressing into a precursor block (2);

s4: by Y ₂ O ₃ Powder pressing Y ₂ O ₃ A support block (3);

s5: assembly blank

Taking 1 Al ₂ O ₃ Gasket (5), 1Y ₂ O ₃ The device comprises a supporting block (3), 1 precursor block (2), a plurality of MgO single crystal blocks (4) and a plurality of neodymium barium copper oxygen seed crystals (1);

assembling in an axisymmetric manner, placing a plurality of MgO single crystal blocks (4) on Al ₂ O ₃ Above the gasket (5), Y ₂ O ₃ The supporting block (3) is arranged above the MgO single crystal block (4), and the precursor block (2) is arranged at Y ₂ O ₃ A plurality of neodymium barium copper oxygen seed crystals (1) are arranged above the support block (3) and above the precursor block (2);

s6: preparing the blank into a textured gadolinium-barium-copper-oxygen block material by using a fused texture growth method;

s7: oxygen permeation treatment

And (3) putting the gadolinium-barium-copper-oxygen block material into an oxygen permeation furnace, quickly heating to 430 ℃, introducing the gadolinium-barium-copper-oxygen block material into the oxygen permeation furnace at a flow of 200ml/min of oxygen, slowly cooling to 350 ℃ after 200 hours, and then cooling to room temperature along with the furnace to obtain the textured gadolinium-barium-copper-oxygen superconducting block material.

2. A method of preparing a melt textured growth of GdBCO superconducting bulk material in combination with a top seed crystal and an internal seed crystal as claimed in claim 1, wherein: the step S1 specifically comprises the following steps:

nd is mixed with ₂ O ₃ With BaCO ₃ Mixing the three powders of CuO uniformly according to the mol ratio of 1:1:1, and preparing Nd by using a solid phase sintering method ₂ BaCuO ₅ The method comprises the steps of carrying out a first treatment on the surface of the Nd is then added ₂ O ₃ With BaCO ₃ 、CuMixing the three powders according to the mol ratio of 1:4:6 uniformly, and preparing NdBa by using a solid phase sintering method ₂ Cu ₃ O _7-δ The method comprises the steps of carrying out a first treatment on the surface of the Then Nd is added ₂ BaCuO ₅ Powder and NdBa ₂ Cu ₃ O _7-δ Uniformly mixing the powder according to the mass ratio of 1:3, pressing into a neodymium barium copper oxygen precursor block, and sintering in a crystal growth furnace by using a top seed crystal melting texture method to obtain a neodymium barium copper oxygen block; taking naturally cleaved neodymium barium copper oxygen small squares as seed crystals;

in the formula, delta is more than or equal to 0 and less than or equal to 1.

3. A method of preparing a melt textured growth of GdBCO superconducting bulk material in combination with a top seed crystal and an internal seed crystal as claimed in claim 1, wherein: the step S6 specifically comprises the following steps:

placing the assembled green body into a crystal growth furnace, firstly heating to 900 ℃ at a heating rate of 80-120 ℃/h, and preserving heat for 10 hours; raising the temperature to 1060 ℃ at the heating rate of 40-60 ℃/h, preserving heat for 1-2 hours, cooling the temperature to below 1040 ℃ at the rate of 60-100 ℃/h, then lowering the temperature to 1020 ℃ at the rate of 0.2-1 ℃/h, and naturally cooling to room temperature along with a furnace to obtain the textured gadolinium-barium-copper-oxygen superconducting bulk material with the top seed crystal and the internal seed crystal combined and induced to grow.

4. A method of preparing a melt textured growth of GdBCO superconducting bulk material in combination with a top seed crystal and an internal seed crystal as claimed in claim 1, wherein: the Y is ₂ O ₃ The size of the supporting block (3) is consistent with that of the precursor block (2).

5. A method of preparing a melt textured growth of GdBCO superconducting bulk material in combination with a top seed crystal and an internal seed crystal as claimed in claim 1, wherein: in the step S5, the neodymium barium copper oxygen seed crystal in the precursor block (2) is provided with k layers, and k is more than or equal to 1; adding a layer of neodymium barium copper oxygen seed crystal on the top of the precursor block (2), wherein the total number of the neodymium barium copper oxygen seed crystals is k+1 layers; the number of the neodymium barium copper oxygen seed crystals (1) placed on the odd layers from top to bottom is m multiplied by n, the number of the neodymium barium copper oxygen seed crystals (1) placed on the even layers is i multiplied by j, m is more than or equal to 1, n is more than or equal to 1, i is more than or equal to 1, and j is more than or equal to 1.

6. A method of preparing a melt textured growth of GdBCO superconducting bulk material in combination with a top seed crystal and an internal seed crystal as claimed in claim 5, wherein: the minimum distance d between adjacent neodymium barium copper oxygen seed crystals (1) on the same layer in the precursor block (2) is more than or equal to 2mm; and the crystal grain orientation of each neodymium barium copper oxygen seed crystal (1) of the same layer is consistent, and the ab surface of each neodymium barium copper oxygen seed crystal (1) is parallel to the upper surface of the precursor block (2).

7. A method of preparing a melt textured growth of GdBCO superconducting bulk material in combination with a top seed crystal and an internal seed crystal as claimed in claim 5, wherein: the orientation of the neodymium barium copper oxygen seed crystals (1) between adjacent layers in the precursor block (2) is consistent, the ab surface of the neodymium barium copper oxygen seed crystals (1) is parallel to the upper surface of the precursor block (2), and the sum of the thicknesses of gadolinium barium copper oxygen crystals obtained by the induced growth of each layer of neodymium barium copper oxygen seed crystals (1) is larger than or equal to the thickness of the precursor block (2).

8. A method of preparing a melt textured growth of GdBCO superconducting bulk material by combining a top seed with an internal seed as claimed in claim 6 or claim 7, wherein: each neodymium barium copper oxygen seed crystal (1) in the precursor block (2) induces the single gadolinium barium copper oxygen crystal grain of growth to be consistent.

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