Process for producing thin superconducting films made of ceramic material

摘要

The invention relates to a process for producing thin superconducting films of compounds of the general formula Mex<III>Mey<II>CuzOn, where Me<III> is a metal selected from the third main group or the lanthanoid group, Me<II> is a metal selected from the second main group of the periodic system of elements and x is a decimal less than 2, y is a decimal (2x) or less than 1 or 1, z is 1 or 3, and n is an integer or a decimal between 4 and 7. In the method, the elements of the compound are sputtered onto a refractory oxygen-resistant substrate in the desired atomic ratio by cathode sputtering. In the method, the elemental constituents of the desired compound present in the film are intended to condense on the substrate with the desired composition and the surface mobility of the copper is to be virtually prevented. This is achieved by combining the following process steps: a) sputtering the metals, or the metals and oxygen, onto the cold substrate until the desired film thickness is reached at a temperature ranging from the temperature of liquid nitrogen up to 200@C, and b) conversion of the amorphous compound formed on the substrate in step a) into a superconducting structure by heating the film to a temperature ranging from 800@C to 1000@C for a time of between one second and one hour.