Process for producing YBCO superconducting thin film target material

Abstract

The invention provides a method for preparing YBCO superconducting film target materials. The method comprises the following: A, a step of preparing YBCO superconducting-phase powder; B, a step of preforming, which is to put the powder prepared in a step A in a die, compress the powder by use of the pressure of between 20 and 30 MPa on a press so as to manufacture a sheet, put the sheet obtained through compression in a rubber sleeve, perform cold isostatic pressing under the pressure of between 150 and 200 MPa and obtain a superconducting sheet; C, a step of sintering the sheet, which is to sinter the superconducting sheet obtained in a step B in a box-type furnace for 20 to 30 hours at a sintering temperature of between 850 and 960 DEG C; and D, a step of performing oxygen permeation, which is to put the superconducting sheet sintered in a step C in a tubular furnace, perform oxygen permeation treatment for 2 to 3 hours at a temperature of between 450 and 500 DEG C and obtain the target material. The target material prepared by the method has the advantages of uniformity, good shape, high density and good superconducting performance. In addition, the method is low in cost and suitable for the mass production of the target material.

Description

technical field [0001] The invention relates to the preparation of a superconducting material, in particular to a method for preparing a YBCO superconducting film target. Background technique [0002] Yttrium barium copper oxide (YBCO) superconducting thin film is widely used in many fields because of its high critical current density and high critical magnetic field. It can be used as a microwave device in the field of microelectronics to achieve the effect of reducing noise; it can be used as a superconducting tape in the field of power transmission; it can be used in superconducting computers or other fields to make superconducting quantum interference devices (SQUID); In the field of magnetic energy storage, it is used to make superconducting coils. Therefore, countries all over the world have paid great efforts for YBCO superconducting thin films. The existing YBCO superconducting film preparation methods include: pulse laser method, magnetron sputtering method, chemi...

AI Technical Summary

Problems solved by technology

During dry pressing, high pressure is applied to the powder in the axial direction at one time, and the pressure is high, and the pressure is applied in a single direction, rather than equal pressure in all directions, so that the internal stress of the formed sheet is large, resulting in The superconducting target is easy to break when demoulding, and the target is damaged; if the pressure is directly reduced, the density of the target will be insufficient, which will eventually affect the quality of the film

2. Hot isostatic pressing: Hot isostatic pressing is performed on superconducting powder, that is, nitrogen or argon is used as the pressurized medium in a heated state, and the superconducting powder in the metal sheath is subjected to hot isostatic pressing to directly make a target It does not need to be sintered, and its disadvantage is that because the high pressure is applied to the powder at one time, it can only be pressed into a thick sheet with a large amount of powder, and finally cut into the required thin sheet, thus forming a waste of superconducting powder; And hot isostatic pressing requires the use of special pressurized media, expensive high-temperature hot isostatic pressing equipment and disposable metal sheaths, so its preparation cost is expensive

Also because it presses and molds the powder at one time, the pressed sheet needs to be cut, resulting in waste of powder. The rubber sheath not only acts as a mold, but also acts as an oil barrier. The performance requirements of the rubber sheath are high, and the cost of the rubber sheath is high.

Its preparation cost is still on the high side, and it is difficult to produce in large quantities

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