Method of manufacturing an electrical contact for a superconductive ceramic

In a method of manufacturing an electrical contact between a current lead and a part made of a superconductive RBa.sub.2 Cu.sub.3 O.sub.y ceramic where R designates a lanthanide selected from the group consisting of Y, La, Nd, Sm, Eu, Gd, Ho, Er, Tm, Yb, and Lu, and where y lies in the range 6.9 to 7, in which method a layer of a material based on a silver-containing resin is deposited on said part, the part is dried, and is then heat treated in oxygen by being heated to a temperature greater than 900.degree. C., and then cooled, with the temperature dwelling at 450.degree. C. for a length of time corresponding to a phase during which said ceramic is reoxygenated, the improvement wherein:

• prior to depositing said layer, the surface of the part is polished to roughness of less than 10 .mu.m, and any grease is then removed therefrom;
• said layer is deposed to a thickness lying in the range of 2 .mu.m to 10 .mu.m and is made of a material based on a cross-linkable resin diluted with a solvent in a concentration lying in the range 40% to 50% by weight, which solvent does not react with the ingredients of said resin, said material containing silver in a concentration lying in the range 30% to 45% by weight of a mixture formed by said resin and said solvent;
• and
• between the drying and the heat treatment, said resin is cross-linked by said part being put in an oven at about 100.degree. C. for about 1 hour.