抄録
Electroless Ag plating was investigated as a method of coating of Al2O3 ceramics with YBCO superconducting oxides. The adhesion strength of the Ag plating increased greatly when the ceramics were pretreated by both mechanical and chemical etchings. From a study on the electrophoretic deposition of superconducting oxides particles from acetone baths, it was found that the amount of deposit increases with the I2 and H2O content of the bath, but excessive addition of I2 or H2O caused an increase in bath conductivity and electrolytic current, resulting in significant hydrogen evolution and a decrease in deposition.
After electrophoretic deposition of the superconducting oxides on the ceramics, the ceramics were heat-treated at 940°C for 6h and at 450°C for 4h. The oxide coating was found to be smooth, uniform, and adhesive, and the superconducting properties of the coating were fully verified by X-ray diffraction, diamagentic measurement, and measurement of resistivity.
Moreover, coil of Ag wire (φ0.7mm) was completely coated with superconducting oxides just like as above. These facts confirmed that electrophoretic deposition is an effective method for the preparation of superconducting oxides on various substrates of various shapes.
