Method for preparing high temperature superconductor thick film of Ba/YCu with large area by using electrophoresis technique

Abstract

A method includes following steps. (1) A metal layer is vaporized on the MgO monocrystal substrate. Then, the substrate is fixed on the negative electrode for stand by application. (2) YBa2Cu3O7-delta sintered is ground till the granularity of the powder is less than 0.1-10 micros. The powder is mixed with organic solvent in mixing ratio being as 20g / liter. The YBa2Cu3O7 delta electrophoresis fluid is prepared by stirring up the organic solvent making the fluid disperse evenly. (3) The YBa2Cu3O7-delta electrophoresis fluid and the electrode with the motorcrystal substrate are put to the cleaned electrophoresis pool. The even YBa2Cu3O7-delta film is obtained after 20-900V DC current being add to electrodes and 5-1600 seconds deposit time being kept.

Description

technical field

[0001] The invention relates to the field of preparation of high-temperature superconducting films, in particular to the preparation of large-area high-temperature superconducting barium yttrium copper oxide (YBa 2 Cu 3 o 7-δ ) thick film method. Background technique

[0002] YB 2 Cu 3 o 7-δ Superconducting film, due to its high superconducting transition temperature and high critical current density, is widely used in the field of microwave and communication, especially in microwave devices such as filters, which has an irreplaceable position. Now prepare YBa 2 Cu 3 o 7-δ The film often adopts pulsed laser deposition method (hereinafter referred to as PLD) and magnetron sputtering method. PLD method can grow YBa with excellent superconducting properties 2 Cu 3 o 7-δ thin film, but its growth rate will slow down with the increase of the film area. Moreover, the difficulty of preparation increases rapidly as the film area becomes larger and thicke...

Examples

Embodiment 1

[0019] Embodiment 1: prepare YBa on the MgO substrate of 10mm * 10mm 2 Cu 3 o 7-δ superconducting thick film.

[0020] What this embodiment uses is the electric pool shown in Fig. 1, and the MgO substrate of 10mm*10mm*0.5mm is vaporized a layer of Ag in advance. In the first step, 2.45 g of YBa 2 Cu 3 o 7-δ powder, fully ground to make the particle size less than 2μm, and then the ground YBa 2 Cu 3 o 7-δ The powder is mixed with 125-1000 milliliters of acetone (purity 99.99%), stirred with a glass rod and then poured into an electric pool. In the second step, the metal silver with a thickness of 0.3 mm, a width of 1.5 cm, and a length of 5 cm is cleaned as the positive and negative electrodes of the battery. The lower end and sides of the negative electrode are bent to fix the substrate, and the Ag-plated MgO substrate is fixed on the negative electrode. In the third step, 900 volts of direct current is applied to the electrodes and maintained for 10 minutes. A laye...

Embodiment 2

[0021] Embodiment 2: prepare YBa on the MgO large substrate of 150mm * 150mm 2 Cu 3 o 7-δ superconducting thick film.

[0022] What this embodiment uses is the electric pool in Fig. 1. The method is similar to that of Example 1, and a layer of Pt is evaporated on the MgO substrate in advance. Electric swimming pool is identical with embodiment 1, YBa 2 Cu 3 o 7-δ The particle size of the powder is less than 0.5 μm, and the electrophoresis solvent uses chloroform. Fix the Pt-coated MgO substrate on the negative electrode, pass a voltage of 900 volts between the positive and negative electrodes, and keep it for 30 minutes. A layer of YBa with a thickness of about 800nm ​​is deposited on the substrate 2 Cu 3 o 7-δ membrane. Will deposit good YBa 2 Cu 3 o 7-δ The film is placed in a sintering furnace, and the temperature of the furnace is raised to 1080°C at a rate of 300-400°C / hour, and maintained for half an hour, and then dropped to 990°C at a rate of 300°C / hour, an...

Embodiment 3

[0023] Embodiment 3: A YBCO thin film is grown on a textured nickel sheet, and MgO is used as an isolation layer.

[0024] The present embodiment uses the electric pool among Fig. 1. The method is similar to that of Example 1. First, a dense and uniform magnesium oxide film (made according to Chinese patent application number: NO.01110033.8) is prepared, and a layer of Al is steamed on the MgO substrate. Electric swimming pool is identical with embodiment 1, YBa 2 Cu 3 o 7-δ The powder particle size is less than 8μm. Fix the Ag / MgO / Ni on the negative electrode, pass a voltage of 900 volts between the positive and negative electrodes, and keep it for 10 minutes. A layer of YBa with a thickness of about 17 μm is deposited on the substrate. 2 Cu 3 o 7-δ . Will deposit good YBa 2 Cu 3 o 7-δ The film is placed in a sintering furnace, and the furnace temperature is raised to 1050°C at a heating rate of 300-400°C / hour, and kept for half an hour, and then dropped to 990°C a...

technical field

[0001] The invention relates to the field of preparation of high-temperature superconducting films, in particular to the preparation of large-area high-temperature superconducting barium yttrium copper oxide (YBa 2 Cu 3 o 7-δ ) thick film method. Background technique

[0002] YB 2 Cu 3 o 7-δ Superconducting film, due to its high superconducting transition temperature and high critical current density, is widely used in the field of microwave and communication, especially in microwave devices such as filters, which has an irreplaceable position. Now prepare YBa 2 Cu 3 o 7-δ The film often adopts pulsed laser deposition method (hereinafter referred to as PLD) and magnetron sputtering method. PLD method can grow YBa with excellent superconducting properties 2 Cu 3 o 7-δ thin film, but its growth rate will slow down with the increase of the film area. Moreover, the difficulty of preparation increases rapidly as the film area becomes larger and thicke...

Examples

Embodiment 1

[0019] Embodiment 1: prepare YBa on the MgO substrate of 10mm * 10mm 2 Cu 3 o 7-δ superconducting thick film.

[0020] What this embodiment uses is the electric pool shown in Fig. 1, and the MgO substrate of 10mm*10mm*0.5mm is vaporized a layer of Ag in advance. In the first step, 2.45 g of YBa 2 Cu 3 o 7-δ powder, fully ground to make the particle size less than 2μm, and then the ground YBa 2 Cu 3 o 7-δ The powder is mixed with 125-1000 milliliters of acetone (purity 99.99%), stirred with a glass rod and then poured into an electric pool. In the second step, the metal silver with a thickness of 0.3 mm, a width of 1.5 cm, and a length of 5 cm is cleaned as the positive and negative electrodes of the battery. The lower end and sides of the negative electrode are bent to fix the substrate, and the Ag-plated MgO substrate is fixed on the negative electrode. In the third step, 900 volts of direct current is applied to the electrodes and maintained for 10 minutes. A laye...

Embodiment 2

[0021] Embodiment 2: prepare YBa on the MgO large substrate of 150mm * 150mm 2 Cu 3 o 7-δ superconducting thick film.

[0022] What this embodiment uses is the electric pool in Fig. 1. The method is similar to that of Example 1, and a layer of Pt is evaporated on the MgO substrate in advance. Electric swimming pool is identical with embodiment 1, YBa 2 Cu 3 o 7-δ The particle size of the powder is less than 0.5 μm, and the electrophoresis solvent uses chloroform. Fix the Pt-coated MgO substrate on the negative electrode, pass a voltage of 900 volts between the positive and negative electrodes, and keep it for 30 minutes. A layer of YBa with a thickness of about 800nm ​​is deposited on the substrate 2 Cu 3 o 7-δ membrane. Will deposit good YBa 2 Cu 3 o 7-δ The film is placed in a sintering furnace, and the temperature of the furnace is raised to 1080°C at a rate of 300-400°C / hour, and maintained for half an hour, and then dropped to 990°C at a rate of 300°C / hour, an...

Embodiment 3

[0023] Embodiment 3: A YBCO thin film is grown on a textured nickel sheet, and MgO is used as an isolation layer.

[0024] The present embodiment uses the electric pool among Fig. 1. The method is similar to that of Example 1. First, a dense and uniform magnesium oxide film (made according to Chinese patent application number: NO.01110033.8) is prepared, and a layer of Al is steamed on the MgO substrate. Electric swimming pool is identical with embodiment 1, YBa 2 Cu 3 o 7-δ The powder particle size is less than 8μm. Fix the Ag / MgO / Ni on the negative electrode, pass a voltage of 900 volts between the positive and negative electrodes, and keep it for 10 minutes. A layer of YBa with a thickness of about 17 μm is deposited on the substrate. 2 Cu 3 o 7-δ . Will deposit good YBa 2 Cu 3 o 7-δ The film is placed in a sintering furnace, and the furnace temperature is raised to 1050°C at a heating rate of 300-400°C / hour, and kept for half an hour, and then dropped to 990°C a...

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