JPH03219095A - Plating method for rare earth-barium-copper alloy - Google Patents

Abstract

PURPOSE:To easily plate rare earth-barium-copper alloy into a uniform film shape by dissolving rare earth, barium and copper as halides into a solvent mixed with dimethyl sulfoxide and pyridine and electrolyzing this soln. CONSTITUTION:The respective halides of rare earth, Ba and Cu are dissolved at the prescribed amount into a solvent mixed with dimethyl sulfoxide and pyridine. Further, the amount of pyridine in the solvent is regulated to a degree wherein precipitate is not formed. Then electrolysis is performed while utilizing the obtained soln. as an electrolyte. Therein a plated layer contg. rare earth, Ba and Cu is formed on a cathode. Thereby rare earth-Ba-Cu alloy plating which is capable of becoming a precursor for obtaining the film of oxide high- temp. superconductive substance RBa2Cu3O7-delta (R shows rare earth) is easily obtained as a uniform film shape at high formation velocity without necessitating an expensive device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing rare earth-barium-copper alloy plating. rare earth)
The present invention relates to a method for producing an alloy film that can be used as a precursor for obtaining a film.

[Conventional technology]

Various methods have been tried to form thin or thick films of high-temperature superconducting materials, including vapor deposition, sputtering, CVD, coating, thermal spraying, electrophoresis, and dispersion composite plating.

[Problem to be solved by the invention]

All of the methods that have been tried to form films of high-temperature superconducting materials have their advantages and disadvantages, and it can be said that they are still in the development stage at present. For example, there are many reports that superconducting films with good characteristics can be obtained using vapor deposition and sputtering methods, but these methods require expensive equipment and have problems such as slow film formation speed. It had

In view of the above-mentioned state of the art, the present invention seeks to provide a method for obtaining a uniform rare earth-barium copper alloy film, which can also be a high-temperature superconducting material, using an alloy plating method without requiring expensive equipment.

[Means to solve the problem]

It is already known that amorphous alloys of rare earth metals, barium, and copper can serve as precursors for high-temperature superconducting materials, and after mixing melts of these metals, the alloy obtained by rapid cooling is heat-treated under appropriate conditions. As a result, there have been several reports showing superconductivity at temperatures around 90°C. (For example, G,
J.

Yurek, J., B., Vander 5ande.
,iv,-X,Wang, D.A.

Rudman, Y., Xhang, and M.
M, Matthiesen ;MBTALLIIRGI
CAL TRANSACTIONS A, Vol.
18A.

p., 1813-1817) According to the alloy plating method, such a precursor can be obtained as a film using inexpensive equipment, the film formation speed is fast, and a uniform film can be formed even on a base material with a somewhat complex shape. It is thought that it is easy to form.

Here, rare earth metals and barium are known as metals that cannot be plated from an aqueous solution.

When attempting to plate such metals, it is generally a common practice to use an organic solvent instead of water as the solvent for the plating solution, but in this case, the selection of the organic solvent used determines whether or not plating is possible. This is one of the important factors. In particular, in the case of alloy plating, it is necessary to commonly dissolve the salts of the target component metals, and to reduce the ions of the target component metals as metals on the cathode under the same electrolytic conditions. Therefore, it is difficult to select an appropriate solvent.

As a result of extensive research into the selection of solvents for producing rare earth-barium-copper alloys by plating, the present inventor found that a mixture of dimethyl sulfoxide and pyridine dissolves rare earth, barium, and copper halides well. It was discovered that an alloy plating layer containing rare earths, barium, and copper is formed on the cathode by electrolysis.

The present invention was completed based on the above knowledge, and electrolysis is carried out using a solution in which rare earth halides, barium halides, and copper halides are dissolved in a mixed solvent of dimethyl sulfoxide and pyridine. In this method, a plating layer containing rare earth elements, barium, and copper is formed on the cathode.

Rare earths include yttrium (Y) and ytterbium (
Yb) and the like are used, but are not particularly limited to these.

Further, as the halides of each metal, chlorides, iodides, etc. are used, but these are also not limited to these.

Furthermore, although the solvent used in the present invention is a mixture of dimethyl sulfoxide and pyridine, a small amount of water may also be present.

[Effect]

Dimethyl sulfoxide is a solvent that can commonly dissolve rare earth halides, barium halides, and copper halides. For example, dimethyl sulfoxide, YCI.

The solution in which BaC1z and CLICI2 were dissolved had a yellow color, and YCI3. The solution in which Ba12 and [:uCI□ were dissolved has a brown color. However, it has been found that when these solutions are electrolyzed, an insulating film is formed on the cathode, making it difficult to pass current and making it impossible to grow plating.

When pyridine is added to this solution, the solvation state of the metal ions changes, giving the solution a greenish color.If this mixed solvent of dimethyl sulfoxide and pyridine is used, alloy plating can be achieved on the cathode by constant current electrolysis. It becomes possible to form layers. Further, the alloy composition can be adjusted by changing the composition of the metal salt in the liquid and the electrolytic conditions (current density and liquid temperature).

Note that if the amount of pyridine is too large, precipitation will occur, so when adding pyridine, it is necessary to use an amount that does not cause precipitation.

[Example 1] First, an electrolytic solution having the following composition was prepared.

At this time, commercially available reagents for dimethyl sulfoxide and pyridine were used as they were without dehydration or purification, and as for the metal salt, commercially available hydrated salts were used as they were. In addition, as a preparation procedure, first add YCl to dimethyl sulfoxide, ・6
H20, Ba12・2820 and CLIC12・2H3
A brown liquid was prepared by dissolving 0, and pyridine was added to this. This electrolyte was green at room temperature and turned brown as the temperature was increased. This liquid was placed in a closed container as shown in Figure 1, and nitrogen gas was passed through it under the following conditions.
In the figure, 1 is an electrolytic solution, 2 is an anode, 3 is a cathode, 4 is a nitrogen gas inlet, 5 is a nitrogen gas outlet, 6 is a power source, and 7 is a constant temperature water bath.

[Example 2] In the electrolyte solution (200 cm3) used in [Example 1], 2
cm' (1vo1%) of water was added and electrolysis was carried out under the following conditions in a nitrogen gas atmosphere in the same manner as in [Example 1], and a black or deep purple electrodeposited substance (film) was obtained on the cathode. Ta. When this deposit was scraped off and examined by plasma emission spectrometry, it was found that each of the elements Y, Ba, and Cu was 2:
It was confirmed that they coexisted at a ratio of 1:5 (atomic ratio).

When electrolysis was carried out, a black or deep purple electrodeposited substance (film) was obtained on the cathode. When this deposit was scraped off and examined by plasma emission spectrometry, it was found that Y, Ba, and Cu
It was confirmed that each element coexisted in the ratio of 3:1:6 (atomic ratio).

[Example 3] First, an electrolytic solution having the following composition was prepared.

At this time, commercially available reagents for dimethyl sulfoxide and pyridine were used as they were without dehydration or purification, and as for the metal salt, commercially available hydrated salts were used as they were. In addition, as a preparation procedure, first add YbCl3 to dimethyl sulfoxide.
6H20, BaI2・2H20 and CuC'l□・2H
A brown liquid was prepared by dissolving 20, and pyridine was added to this. This electrolyte was green at room temperature and turned brown as the temperature was increased. Using this electrolytic solution, electrolysis was carried out under the following conditions in a nitrogen gas atmosphere as in [Example 1], and a black deposit (film) was obtained on the cathode. When this deposit was scraped off and examined by plasma emission spectrometry, it was found that each element of Yb, Ba, and Cu was present at 1%.
It was confirmed that they coexisted at a ratio of 2:1 near 2 (atomic ratio).

〔Effect of the invention〕

According to the present invention, a rare earth-Ba-Cu alloy that can be a precursor of a high-temperature superconducting material can be easily obtained in the form of a uniform film without requiring expensive equipment.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an electroplating apparatus employed in carrying out the present invention.

Claims (1)

[Claims] (1) Electrolysis is performed using a solution in which rare earth halides, barium halides, and copper halides are dissolved in a mixed solvent of dimethyl sulfoxide and pyridine, and rare earths, barium, and copper are contained on the cathode. A rare earth-barium-copper alloy plating method characterized by forming a plating layer.