Melt-produced high temperature rare earth barium copper oxide superconductor and processes for making same

A method for making a superconductor comprising the steps of:

• mixing and grinding BaCO.sub.3 and CuO with nominal compositions of at least one compound chosen from the group consisting of Ba.sub.2 Cu.sub.3 O.sub.5, BaCu.sub.3 O.sub.4, BaCu.sub.4 O.sub.5, BaCu.sub.6 O.sub.7, and BaCu.sub.12 O.sub.13 ;
• heating the resultant mixture;
• pressing the resultant mixture into a pellet;
• placing the pellet on a preheated powder comprising RBa.sub.2 Cu.sub.3 O.sub.4.5 F.sub.4 wherein R is chosen from the group consisting of:
• Gd, Ho, Er, Yb, Nd, Sm, Eu, Dy, Tm, and Lu;
• heating the pellet and the powder in a furnace to approximately 940.degree. to about 1000.degree. C. to form a melt at a powder:powder interface;
• and
• removing a melted interface between the pellet and powder.

A method for making a superconductor comprising the steps of:

• mixing and grinding BaCO.sub.3 and CuO with nominal compositions of at least one compound chosen from the group consisting of Ba.sub.2 Cu.sub.3 O.sub.5, BaCu.sub.3 O.sub.4, BaCu.sub.4 O.sub.5, BaCu.sub.6 O.sub.7, and BaCu.sub.12 O.sub.13 ;
• heating the resultant mixture;
• pressing the resultant mixture into a pellet;
• placing the pellet on a powder that has previously been heated comprising R.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 wherein R is chosen from the group consisting of:
• Y, Gd, Er, Ho, Nd, Sm, Eu, Yb, Dy, Tm, and Lu;
• heating the pellet and the powder in a furnace to a temperature of greater than or equal to 950.degree. C. and less than or equal to 1000.degree. C. to form a melt at a pellet:powder interface;
• and
• removing the melt-produced superconductor from the powder in which the superconductor is embedded.

A method for making a superconductor comprising the steps of:

• mixing and grinding BaCO.sub.3 and CuO with nominal compositions of at least one compound chosen from the group consisting of BaCu.sub.3 O.sub.5, Ba.sub.2 Cu.sub.3 O.sub.4, BaCu.sub.4 O.sub.5, BaCu.sub.6 O.sub.7, and BaCu.sub.12 O.sub.13 ;
• heating the resultant mixture to a temperature of approximately 900.degree. C.;
• pressing the resultant mixture into a pellet;
• placing the pellet on a preheated powder comprising Y.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 ;
• heating the pellet and the powder in a furnace to a temperature of greater than or equal to 940.degree. C. and less than or equal to 1000.degree. C. for approximately 12 to about 24 hours to form a melt at a pellet:powder interface;
• cooling the furnace to approximately 650.degree. C. and heating the pellet and powder therein;
• cooling the furnace to at least approximately 200.degree. C.;
• and
• removing a melted interface between the pellet and powder.

A method for making a superconductor comprising the steps of:

• placing a pellet consisting of a compound chosen from the group consisting of Ba.sub.2 Cu.sub.3 O.sub.5, BaCu.sub.3 O.sub.4, and BaCu.sub.4 O.sub.5 on a powder consisting of a compound chosen from the group consisting of RBa.sub.2 Cu.sub.3 O.sub.4.5 F.sub.4, R.sub.1.2 Ba.sub.0.8 CuO.sub.3.6, R.sub.2 O.sub.3, and RBa.sub.2 O.sub.3.5 wherein R is chosen from the group of rare earth metals excluding Tb, Pr, and Ce;
• heating the pellet and powder to approximately 950.degree. C. to about 1000.degree. C. for 12 to 24 hours to form a melt at a pellet:powder interface;
• and
• removing a melted interface between the pellet and powder.

A method of making a superconductor comprising the steps of:

• placing a pellet consisting of BaCu.sub.3 O.sub.4 on a powder consisting of HoBa.sub.2 O.sub.3.5 ;
• heating the pellet and powder to approximately 940.degree. C. to 1000.degree. C. to form a melt at a pellet:powder interface;
• and
• removing a melted interface between the pellet and powder.

A method of making a superconductor comprising the steps of:

• placing a pellet consisting of BaCu.sub.3 O.sub.4 on a powder consisting of HoSrO.sub.2.5 ;
• heating the pellet and powder to approximately 950.degree. C. to 1000.degree. C. to form a melt at a pellet:powder interface;
• and
• removing a melted interface between the pellet and powder.

A process of making melt-produced superconductor components of arbitrary shape comprising the steps of:

• mixing and grinding BaCO.sub.3 and CuO in a nominal composition of BaCu.sub.3 O.sub.4 ;
• heating the mixture in air at about 900.degree. C. for about 12 hours, cooling the mixture, and grinding it;
• mixing and grinding Y.sub.2 O.sub.3, BaCO.sub.3, and CuO in a nominal composition of Y.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 ;
• heating the mixture in air at about 950.degree. C. for about 12 hours, then cooling it and grinding it;
• pressing the BaCu.sub.3 O.sub.4 powder into an arbitrary shape and placing it onto the Y.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 powder;
• heating the BaCu.sub.3 O.sub.4 and Y.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 in a furnace in flowing O.sub.2 at about 950.degree. C. for about 12 hours to form a melt at a shape:powder interface;
• holding the furnace at 650.degree. C. for about 4 hours;
• cooling the furnace to less than 200.degree. C. and removing from the furnace heated materials to bring them to room temperature;
• and
• separating a black melt-produced superconductor from the remaining Y.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 powder in which the superconductor is embedded.

A method for making a superconductor comprising the steps of:

• mixing and grinding BaCO.sub.3 and CuO with nominal compositions of at least one compound selected from the group consisting of Ba.sub.2 Cu.sub.3 O.sub.5, BaCu.sub.3 O.sub.4, BaCu.sub.4 O.sub.5, BaCu.sub.6 O.sub.7, and BaCu.sub.12 O.sub.13 ;
• heating the resultant mixture to approximately 850.degree. C. to about 920.degree. C.;
• pressing the resultant mixture into a pellet;
• placing the pellet on a powder preheated to approximately 900.degree. C. to about 1000.degree. C., comprising RBa.sub.2 Cu.sub.3 O.sub.4.5 F.sub.4 wherein R is chosen from the group consisting of:
• Gd, Ho, Er, Yb, Nd, Sm, Eu, Dy, Tm, and Lu;
• heating the pellet and the powder in a furnace to approximately 940.degree. C. to about 1000.degree. C.;
• and
• removing a melted interface between the pellet and powder.

A method for making a superconductor comprising the steps of:

• mixing and grinding BaCO.sub.3 and CuO with nominal compositions of at least one compound chosen from the group consisting of Ba.sub.2 Cu.sub.3 O.sub.5, BaCu.sub.3 O.sub.4, BaCu.sub.4 O.sub.5, BaCu.sub.6 O.sub.7, and BaCu.sub.12 O.sub.13 ;
• heating the resultant mixture to approximately 850.degree. C. to 920.degree. C.;
• pressing the resultant mixture into a pellet;
• placing the pellet on a powder that has previously been heated to approximately 900.degree. C. to about 1000.degree. C., comprising R.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 wherein R is chosen from the group consisting of:
• Y, Gd, Er, Ho, Nd, Sm, Eu, Yb, Dy, Tm, and Lu;
• heating the pellet and the powder in a furnace to a temperature of greater than or equal to 950.degree. C. and less than or equal to 1000.degree. C. to form a melt at a pellet:powder interface;
• and
• removing a melt-produced superconductor from the powder in which the superconductor is embedded.

A method for making a superconductor comprising the steps of:

• mixing and grinding BaCO.sub.3 and CuO with nominal compositions of at least one compound chosen from the group consisting of BaCu.sub.3 O.sub.5, Ba.sub.2 Cu.sub.3 O.sub.4, BaCu.sub.4 O.sub.5, BaCu.sub.6 O.sub.7, and BaCu.sub.12 O.sub.13 ;
• heating the resultant mixture to a temperature of approximately 900.degree. C.;
• pressing the resultant mixture into a pellet;
• placing the pellet on a powder preheated to approximately 900.degree. C. to about 1000.degree. C., comprising Y.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 ;
• heating the pellet and the powder in a furnace to a temperature of greater than or equal to 940.degree. C. and less than or equal to 1000.degree. C. for approximately 12 to about 24 hours to form a melt at a pellet:powder interface;
• cooling the furnace to approximately 650.degree. C. and heating the pellet and powder therein;
• cooling the furnace to at least approximately 200.degree. C.;
• and
• removing a melted interface between the pellet and powder.

A process of making melt-produced superconductor components comprising the steps of:

• mixing and grinding BaCO.sub.3 and CuO in a nominal composition of BaCu.sub.3 O.sub.4 ;
• heating the mixture in air at about 900.degree. C. for about 12 hours, cooling the mixture, and grinding it, and pressing it into a pellet;
• mixing and grinding Y.sub.2 O.sub.3, BaCO.sub.3, and CuO in a nominal composition of Y.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 ;
• heating the mixture in air at about 950.degree. C. for about 12 hours, then cooling it and grinding it;
• placing the resultant BaCu.sub.3 O.sub.4 pellet onto the Y.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 powder;
• heating the BaCu.sub.3 O.sub.4 and Y.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 in flowing O.sub.2 at about 950.degree. C. for about 12 hours to form a melt at the pellet:powder interface;
• holding the furnace at 650.degree. C. for about 4 hours;
• cooling the furnace to less than 200.degree. C. and removing from the furnace the heated materials to bring them to room temperature;
• and
• separating a black melt-produced superconductor from the remaining Y.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 powder.

A process for making melt-produced superconductor components of arbitrary shape comprising the steps of:

• mixing and grinding BaCO.sub.3 and CuO in a nominal composition of BaCu.sub.3 O.sub.4 ;
• heating the mixture in air at about 900.degree. C. for about 12 hours, cooling the mixture, and grinding it;
• mixing and grinding Y.sub.2 O.sub.3, BaCO.sub.3, and CuO in a nominal composition of Y.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 powder;
• heating the mixture in air at about 950.degree. C. for about 12 hours, then cooling it and grinding it;
• pressing the BaCu.sub.3 O.sub.4 powder into an arbitrary shape and placing it onto the Y.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 powder;
• heating the BaCu.sub.3 O.sub.4 and Y.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 in flowing O.sub.2 at about 950.degree. C. for about 12 hours to form a melt at the pellet:powder interface;
• holding the furnace at 650.degree. C. for about 4 hours;
• cooling the furnace to less than 200.degree. C. and removing from the furnace the heated materials to bring them to room temperature;
• and
• separating a black melt-produced superconductor from the remaining Y.sub.1.2 Ba.sub.0.8 CuO.sub.3.6 powder in which the superconductor is embedded.