Method of forming a superconducting oxide layer by MOCVD

A method of forming a copper oxide HTSC material layer on a substrate wherein the copper oxide HTSC material comprises, in addition to copper and oxygen, element(s) for forming the copper oxide HTSC material layer, comprising depositing on said substrate by chemical vapor deposition, from organosource reagent(s) therefor, copper and said element(s), wherein said element(s) and copper are deposited in stoichiometrically correct ratios to one another, and with exposure to an oxidizing gas, to form a deposited material layer containing copper, oxygen, and said element(s), and treating the deposited material layer at elevated temperature to yield said copper oxide HTSC material;

• wherein said element(s) include(s) at least one metal M selected from the group consisting of barium, calcium, and strontium, and said organosource reagent(s) for said element(s) include a metalorganic complex of the formula
• MA.sub.2 X
• wherein:
• A is a monodentate or multidentate organic ligand coordinated to M which allows complexing of MA.sub.2 with ligand X and which forms a stable STP sub-complex MA.sub.2 X with M;
• each of the A ligands can be the same or different;
• and
• X is a monodentate or multidentate ligand coordinated to M and containing one or more atoms independently selected from the group consisting of atoms of the elements C, N, H, S, O, and F.

A method of forming a layer of 123 YBaCuO superconducting material on a substrate, comprising

• (a) forming on the substrate a layer of YBaCuO material which is barium-rich and copper-rich relative to the 123 stoichiometry;
• (b) heating the barium-rich and copper-rich YBaCuO material to an elevated temperature in the range of from about 735.degree. C. to about 860.degree. C. in a stream of inert gas saturated with water vapor;
• (c) maintaining the elevated temperature and gas environment conditions of step (b) for a time of from 10 minutes to about 35 minutes;
• (d) discontinuing exposure of the YBaCuO material, and exposing said YBaCuO material to a stream of oxygen at said elevated temperature for a period of from 1 to 15 minutes;
• (e) heating the YBaCuO material to a temperature of from about 880.degree. C. to about 950.degree. C. in a stream of oxygen, at a heating rate of from about 1.degree. C./minute to about 25.degree. C./minute;
• (f) maintaining the uppermost elevated temperature condition of step (e) for a period of from about 10 to about 30 minutes;
• (g) cooling the YBaCuO material to a temperature of from about 450.degree. to about 600.degree. C. in a stream of oxygen, at a cooling rate of from about 0.5.degree. C./minute to about 5.degree. C./minute;
• and
• (h) quenching the YBaCuO material to room temperature.

A method of treating amorphous YBaCuOF material deposited on a substrate to form a 123 YBaCuO material, comprising the steps of

• (a) heating the YBaCuO material to an elevated temperature in the range of from about 650.degree. C. to about 760.degree. C. in a stream of inert gas saturated with water;
• (b) maintaining the maximum temperature and gas exposure conditions of step (a) for a period of from about 15 minutes to about 2 hours;
• (c) discontinuing the presence of water vapor in the stream of inert gas, and concurrently cooling the YBaCuO material to a temperature in the range of from about 600.degree. C. to about 700.degree. C., at a cooling rate of from about 5.degree. C./minute to about 25.degree. C./minute;
• (d) maintaining the lower cooling temperature of step (c) for a period of from about three to about 5.5 hours in the inert gas stream;
• (e) discontinuing the stream of inert gas, and cooling the YBaCuO material to a temperature of from about 600.degree. C. to about 500.degree. C. in an oxygen stream, at a cooling rate of from about 0.5 to about 5.degree. C./minute;
• (f) maintaining the lower cooling temperature of step (e) in the flowing oxygen stream for a period of from about 8 to about 15 hours;
• and
• (g) quenching the YBaCuO material to room temperature.