Chemical polishing of surfaces of high temp. ceramic superconductors - using dilute acid which is further diluted and removed followed by rinsing with solvent

摘要

The surface of a Cu-contg. ceramic superconductor is chemically etched by (a) flooding the surface with an acid soln., pref. a mineral or aliphatic acid, in a water soln.; (b) diluting the acid soln. by the addn. of solvent, and (c) removing the diluted acid soln. from the surface and rinsing the surface with solvent. The solvent used is pref. water or methanol, and the pref. acid concn. is max 5 vol. %. The mineral acid used is pref nitric, sulphuric, phosphoric and esp. hydrochloric acid, in a concn. of 0.2-3, (0.4-0.8) vol. % in water. The organic acids pref. are formic and esp. acetic acid. A trace of a surfactant is pref. added to the acid soln. After etching, the surface is pref. rinsed in a water-free solvent, pref. acetone.