Thallium(tl)-(e.g., Tl2cabacu308) Patents (Class 505/783)
  • Patent number: 5278139
    Abstract: A superconducting material and a process for producing a superconducting material comprising a compound oxide represented by the general formula:(Ba, .gamma.).sub.x (.alpha.,.beta.).sub.1 -.sub.x .epsilon..sub.y Cu.sub.1-y O.sub.3 -zin which".gamma." represents an element of the IIa group of the periodic table except Ba, an atomic ratio of .gamma. to Ba, being selected in a range between 1% and 90%,".alpha.represents Y or La,".beta." represents an element of the IIIa group of the periodic table but is different from .alpha., an atomic ratio of .beta. to .alpha. being selected in a range between 1 and 90%,".epsilon." represents a metal element of the IIIb group of the periodic table,x, y and z are numbers each satisfies ranges of O.ltoreq.x.ltoreq.1, O.ltoreq.y.ltoreq.1, and O.ltoreq.z.ltoreq.1 respectively, andthe expression of (Ba, .gamma.) and (.alpha., .beta.) mean that the respective elements occupy predetermined sites in a crystal in a predetermined proportion.
    Type: Grant
    Filed: February 25, 1992
    Date of Patent: January 11, 1994
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hideo Itozaki, Saburo Tanaka, Nobuhiko Fujita, Shuji Yazu, Tetsuji Jodai
  • Patent number: 5264414
    Abstract: Compositions having the formula Tl.sub.1-x Bi.sub.x Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.9 wherein x is from about 3/20 to about 11/20 are superconducting with transition temperatures above 110 K. Processes for making and using the compositions of the invention are provided.
    Type: Grant
    Filed: September 25, 1992
    Date of Patent: November 23, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Munirpallam A. Subramanian
  • Patent number: 5262393
    Abstract: The present invention provides a layered copper oxide as an insulator for superconductor or as a superconductor, which has a chemical composition represented by the formula of (R,Ce).sub.3 Sr.sub.2 Cu.sub.2 (M,Cu)O.sub.11, wherein R is a rare earth element other than Ce and M is one or both of Pb and T1, and has a crystal structure comprising a (M,Cu)Sr.sub.2 (R,Ce)Cu.sub.2 O.sub.7 ; unit of a TlBa.sub.2 CaCu.sub.2 O.sub.7 (1-2-1-2)-type structure and a [(R,Ce)O.sub.2 ].sub.2 unit of a fluorite-type structure alternately put on each other, or a chemical composition represented by the formula of (R,Ce).sub.3 Sr.sub.2 Cu.sub.2 (M,Cu)O.sub.10+z, wherein R is a rare earth element other than Ce, M is one or both of Pb or Tl, and has a crystal structure comprising a (R,Ce)Sr.sub.2 Cu.sub.2 (Cu,M)O.sub.6+z unit of a YBa.sub.2 Cu.sub.3 O.sub.3 O.sub.6+.delta. -type structure and a [(R,Ce)O.sub.2 ].sub.2 unit of a fluorite-type structure alternately put on each other, wherein z is in the range of 0.ltoreq.z.ltoreq.
    Type: Grant
    Filed: October 25, 1991
    Date of Patent: November 16, 1993
    Assignees: Matsushita Electric Industrial Co., Ltd., International Superconductivity Technology Center, Central Research Institute of Electric Power Industry, Ube Industries, Ltd.
    Inventors: Takahiro Wada, Ataru Ichinose, Kazuyuki Hamada, Hisao Yamauchi, Shoji Tanaka
  • Patent number: 5258363
    Abstract: A high efficiency integrating sphere that can be used in a large variety of scientific instruments. The sphere having an efficiency gain obtained by using a superconducting material, acting as a perfect reflector, on the inside hollow surface of the sphere. The sphere is operated with a delay between the incident and sensed light, heretofore not possible, and yielding substantial improvement in the signal-to noise ratio of the integrating sphere.
    Type: Grant
    Filed: March 21, 1989
    Date of Patent: November 2, 1993
    Assignee: Troy Investments Inc.
    Inventor: Aharon Z. Hed
  • Patent number: 5258365
    Abstract: The present invention provides a high temperature superconductor system comprising XTlSrCaCuO wherein X is chosen from the group consisting of Cr, Mo, and W. In a preferred embodiment, the superconductor comprises CrTlSrCaCuO. Methods of making the superconductor system are also provided.
    Type: Grant
    Filed: January 22, 1992
    Date of Patent: November 2, 1993
    Assignee: The University of Arkansas
    Inventor: Zhengzhi Sheng
  • Patent number: 5256635
    Abstract: A high temperature superconducting system has the general composition Tl-R-X-Y, wherein: R is a Group 2A element; X is a Group 1B element; and Y is a Group 6A element. Preferably, the composition has the following formula Tl-Ba-Cu-O. The high temperature superconductor of the present invention has a transition temperature of about 90 K with the probability of one phase superconducting at a temperature perhaps as high as 270 K. Processes for making the high temperature superconductor are also provided.
    Type: Grant
    Filed: January 13, 1989
    Date of Patent: October 26, 1993
    Assignee: University of Arkansas
    Inventors: Zhengzhi Sheng, Allen M. Hermann
  • Patent number: 5250510
    Abstract: A now superconducting material comprising a compound oxide represented by the general formula:(Ba, Ca).sub.x (.alpha., Dy).sub.1-x Tl.sub.y Cu.sub.1-y O.sub.3-zwherein".alpha." represents Y or La;the atomic ratio of Ca to Ba is between 1% and 90%;the atomic ratio of Dy to .alpha. is between 1% and 90%;x, y and z are within the ranges of 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, and 0.ltoreq.z<1 respectively; andthe expression of (Ba, Ca) and (.alpha., Dy) mean that the respective elements occupy predetermined sites in a crystal in a predetermined proportion.
    Type: Grant
    Filed: June 15, 1992
    Date of Patent: October 5, 1993
    Assignee: Sumitomo Electric Industries Ltd.
    Inventors: Hideo Itozaki, Saburo Tanaka, Nobuhiko Fujita, Shuji Yazu, Tetsuji Jodai
  • Patent number: 5242897
    Abstract: Complex superconducting oxides are fabricated through appropriate selection and use of fundamental superconducting "building blocks." In this fashion, the invention provides a rationalized method of fabricating complex oxides having desirably high T.sub.c values. In another aspect of the invention, novel, 112 and 12 superconducting oxides are described.
    Type: Grant
    Filed: October 28, 1991
    Date of Patent: September 7, 1993
    Assignee: The University of Kansas
    Inventors: Kai W. Wong, Xin Fei
  • Patent number: 5236889
    Abstract: 1. In the (Bi,Tl)-Ca-(Sr,Ba)-Cu-O based superconducting ceramics production process, a process for preparing superconducting ceramics characterized by(a) providing powders includingi) a compound of Bi oxide or Tl oxide,ii) a Ca compound,iii) an Sr compound or Ba compound, andiv) a Cu compoundas starting powders;(b) compounding and mixing powders from compounds of the starting powders, the compounds each having lower vapor pressure, i.e., powders from compound ii), compound iii), and compound iv) at a compounding ratio to obtain a mixture, and primarily calcining the mixture at a temperature of 850.degree. to 1050.degree. C., to form a Ca--(Sr,Ba)--Cu--O based oxide; and(c) further mixing the Ca--(Sr,Ba)--Cu--O based oxide with a compound having a higher vapor pressure, that is, the powder of compound i), at a compounding ratio, and secondarily calcining at a temperature of 500.degree. to 820.degree. C.
    Type: Grant
    Filed: November 27, 1989
    Date of Patent: August 17, 1993
    Assignee: Mitsubishi Materials Corporation
    Inventors: Tadashi Sugihara, Takuo Takeshita, Yukihiro Ouchi, Takeshi Sakurai
  • Patent number: 5219833
    Abstract: Compositions containing a crystalline phase of the formula Tl.sub.2 Ba.sub.2 CuO.sub.6+x wherein x is from 0 to 0.5. Processes for manufacturing such compositions and for using them are disclosed.
    Type: Grant
    Filed: September 30, 1991
    Date of Patent: June 15, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Jagannatha Gopalakrishnan, Munirpallam A. Subramanian
  • Patent number: 5217949
    Abstract: Superconducting materials of the (T1,In)-Sr-Ca-Cu-O system-type are modified to raise their critical tempertures by substituting an element M for part of the Tl/In and optionally substituting Y or a rare earth element for some of the Ca.M is a transition metal with valency electrons in d orbitals in its normal state and having accessible tri-and/or tetra-valent states, that is V, Ti, Cr, Zr, Nb, Hf or Ta (which are preferred) Mn, Fe, Co, Ni, Mo, Rh, W, Os, Ir, Re or Ru.
    Type: Grant
    Filed: April 16, 1991
    Date of Patent: June 8, 1993
    Assignee: Lynxvale Limited
    Inventors: Ru-Shi Liu, Robert Janes, Wuzong Zhou, Peter P. Edwards
  • Patent number: 5215962
    Abstract: A high temperature superconductor system having the nominal composition: Tl-Ba-Ce-Cu-O. The high temperature superconductor of the present invention has a transition temperature of about 90 K. Processes for making the high temperature superconductor are also provided.
    Type: Grant
    Filed: October 15, 1991
    Date of Patent: June 1, 1993
    Assignee: The University of Arkansas
    Inventors: J. H. Wang, Zhengzhi Sheng, Allen M. Hermann
  • Patent number: 5202306
    Abstract: An oxide-based strengthening and toughening agent, such as tetragonal Zro.sub.2 particles, has been added to copper oxide superconductors, such as superconducting YBa.sub.2 Cu.sub.3 O.sub.x (123) to improve its fracture toughness (K.sub.IC). A sol-gel coating which is non-reactive with the superconductor, such as Y.sub.2 BaCuO.sub.5 (211) on the ZrO.sub.2 particles minimized the deleterious reactions between the superconductor and the toughening agent dispersed therethrough. Addition of 20 mole percent ZrO.sub.2 coated with 211 yielded a 123 composite with a K.sub.IC of 4.5 MPa(m).sup.0.5.
    Type: Grant
    Filed: September 18, 1991
    Date of Patent: April 13, 1993
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Kenneth C. Goretta, Marc L. Kullberg
  • Patent number: 5175140
    Abstract: A new high Tc superconducting compound oxide material represented by the general formula:AuBvCwCuxOyin which"A" is selected from the group consisting of magnesium(Mg), calcium(Ca), strontium(Sr) and barium(Ba);"B" is selected from the group consisting of yttrium(Y), lanthanum(La), and lanthanide elements;"C" is selected from the group consisting of vanadium (V), tantalum(Ta), indium(In), and thallium(Tl), and ##EQU1##
    Type: Grant
    Filed: August 3, 1990
    Date of Patent: December 29, 1992
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Nobuhiko Fujita, Tadakazu Kobayashi, Hideo Itozaki, Saburo Tanaka, Shuji Yazu, Tetsuji Jodai
  • Patent number: 5164362
    Abstract: A high temperature superconductor having the formula Tl-Sr-Ca-Cu-O and a transition temperature about 70 K (with some evidence of a 100 K phase) is provided. Processes for making high temperature superconductors are also provided.
    Type: Grant
    Filed: September 29, 1988
    Date of Patent: November 17, 1992
    Assignee: University of Arkansas
    Inventors: Allen M. Hermann, Zhengzhi Sheng
  • Patent number: 5149687
    Abstract: An oriented superconducting material may be made by cold pressing a nonoriented superconducting material selected from the group consisting of Bi.sub.1, Bi.sub.2, Tl.sub.1, Tl.sub.2, Pb substituted Bi.sub.1, Pb substituted Bi.sub.2, Pb substituted Tl.sub.1, and Pb substituted Tl.sub.2 superconductor materials at a pressure sufficient to form an oriented superconducting material.
    Type: Grant
    Filed: April 1, 1991
    Date of Patent: September 22, 1992
    Assignee: United Technologies Corporation
    Inventor: Francis S. Galasso
  • Patent number: 5145834
    Abstract: A new high temperature superconducting system with transition temperature above 120 K is disclosed. One superconductor in that system in a preferred embodiment comprises TlRBaCuO wherein R is chosen from Group 2A elements excluding Ba. In a preferred embodiment, the superconductor is TlCaBaCuO. In another preferred embodiment, the superconductor comprises TlSrCuO. Processes for making high temperature superconducting system are also disclosed.
    Type: Grant
    Filed: August 26, 1991
    Date of Patent: September 8, 1992
    Assignee: University of Arkansas
    Inventors: Allen M. Hermann, Zhengzhi Sheng
  • Patent number: 5139998
    Abstract: Methods and reactors are described for the production of thallium cuprate based high temperature superconductor films on a variety of substrates. The reactors provide for low volume cavities, means for rapidly heating and cooling to and from a predetermined elevated temperature and control of the thallium oxide overpressure during the processing. Uniform high temperature superconducting films are obtained while inhibiting reaction between the substrate and superconducting film during the processing.
    Type: Grant
    Filed: April 27, 1990
    Date of Patent: August 18, 1992
    Assignee: Superconductor Technologies, Inc.
    Inventors: Michael M. Eddy, William L. Olson, Timothy W. James
  • Patent number: 5120704
    Abstract: High T.sub.c superconducting compounds are made by forming a reaction mixture of the oxides of Sr, Cu, Ca and Tl, compressing these into a hardened body, and placing the hardened body into a container. The container is then evacuated and sealed. The hardened body is heated under pressure until the oxides of Sr, Ca, Cu, and Tl react to form a superconducting compound.
    Type: Grant
    Filed: November 8, 1989
    Date of Patent: June 9, 1992
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: William L. Lechter, Michael S. Osofsky, Earl F. Skelton, Louis E. Toth
  • Patent number: 5106830
    Abstract: A high temperature superconducting system has the general composition Tl-R-X-Y, wherein: R is a Group 2A element; X is a group 1B element; and Y is a Group 6A element. Preferably, the composition has the following formula Tl-Ba-Cu-O. The high temperature superconductor of the present invention has a transition temperature of about 90 K with the probability of one phase superconducting at a temerature perhaps as high as 270 K. Processes for making the high temperature superconductor are also provided.
    Type: Grant
    Filed: April 19, 1990
    Date of Patent: April 21, 1992
    Assignee: University of Arkansas
    Inventors: Zhengzhi Sheng, Allen M. Hermann
  • Patent number: 5100866
    Abstract: A superconducting material and a process for producing a superconducting material comprising a compound oxide represented by the general formula:(Ba, .gamma.).sub.x (.alpha.,.beta.).sub.1 -.sub.x .epsilon..sub.y Cu.sub.1-y O.sub.3-zin which".gamma." represents an element of the IIa group of the periodic table except Ba, and atomic ratio of .gamma. to Ba, being selected in a range between 1% and 90%,".alpha." represents Y or La,".beta." represents an element of the IIIa group of the periodic table but is different from .alpha., an atomic ratio of .beta. to .alpha. being selected in a range between 1 and 90%,".epsilon." represents a metal element of the IIIb group of the periodic table, x, y and z are numbers each satisfies ranges of 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, and 0.ltoreq.z.ltoreq.1 respectively, andthe expression of (Ba, .gamma.) and (.alpha.,.beta.) mean that the respective elements occupy predetermined sites in a crystal in a predetermined proportion.
    Type: Grant
    Filed: October 26, 1989
    Date of Patent: March 31, 1992
    Assignee: Sumitomo Electric Industries Ltd.
    Inventors: Hideo Itozaki, Saburo Tanaka, Nobuhiko Fujita, Shuji Yazu, Tetsuji Jodai
  • Patent number: 5093312
    Abstract: A superconducting material and a process for producing a superconducting material comprising a compound oxide represented by the general formula:(Ba, .gamma.).sub.x (.alpha.,.beta.).sub.1-x .epsilon..sub.y Cu.sub.1-y O.sub.3-zin which".gamma." represents an element of the IIa group of the periodic table except Ba, an atomic ratio of .gamma. to Ba, being selected in a range between 1% and 90%,".alpha." represents Y or La,".beta." represents an element of the IIIa group of the periodic table but is different from .alpha., and atomic ratio of .beta. to .alpha. being selected in a range between 1 and 90%,".epsilon." represents a metal element of the IIIb group of the periodic table, x, y and z are numbers each satisfies ranges of 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, and 0.ltoreq.z.ltoreq.1 respectively, andthe expression of (Ba, .gamma.) and (.alpha., .beta.) mean that the respective elements occupy predetermined sites in a crystal in a predetermined proportion.
    Type: Grant
    Filed: October 26, 1989
    Date of Patent: March 3, 1992
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hideo Itozaki, Saburo Tanaka, Nobuhiko Fujita, Shuji Yazu, Tetsuji Jodai
  • Patent number: 5082825
    Abstract: A process of making high-temperature Tl-based superconductors. The process includes the steps of reacting solid Ba-Ca-Cu-oxides with Tl.sub.2 O.sub.3 vapor. The process allows high quality Tl-based superconductors to be easily fabricated.
    Type: Grant
    Filed: August 25, 1988
    Date of Patent: January 21, 1992
    Assignee: University of Arkansas
    Inventors: Allen M. Hermann, Zhengzhi Sheng
  • Patent number: 5073536
    Abstract: A new high temperature superconductor with transition temperature above 120 K. is disclosed. The superconductor in a preferrred embodiment comprises TlRBaCuO wherein R is chosen from Group 2A elements excluding Ba. In another preferred embodiment, the superconductor comprises TlSrCuO. Processes for making high temperature superconductors are also disclosed.
    Type: Grant
    Filed: March 26, 1990
    Date of Patent: December 17, 1991
    Assignee: The University of Arkansas
    Inventors: Zhengzhi Sheng, Allen M. Herman
  • Patent number: 5066635
    Abstract: A new high temperature superconducting system with transition temperature above 120 K is disclosed. One superconductor in that system in a preferred embodiment comprises TlRBaCuO wherein R is chosen from Group 2A elements excluding Ba. In a preferred embodiment, the superconductor is TlCaBaCuO. In another preferred embodiment, the superconductor comprises TlSrCuO. Processes for making high temperature superconducting system are also disclosed.
    Type: Grant
    Filed: February 9, 1989
    Date of Patent: November 19, 1991
    Assignee: The University of Arkansas
    Inventors: Zhengzhi Sheng, Allen M. Hermann
  • Patent number: 5036044
    Abstract: A high temperature superconductor system is provided having the following formula: M-A-B-C-D-E, wherein, M is a metallic element, A is an element in Group 3A, B is an element in Group 2A, C is another element in Group 2A, D is an element in Group 1B, and E is an element in Group 6A. In an embodiment, the high temperature superconductor has the following formula: R-Tl-Sr-Ca-Cu-O (wherein R is chosen from the group consisting of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y). Processes for making these high temperature superconductors are also disclosed.
    Type: Grant
    Filed: September 29, 1988
    Date of Patent: July 30, 1991
    Assignee: University of Arkansas
    Inventors: Allen M. Hermann, Zhengzhi Sheng
  • Patent number: 5021400
    Abstract: Improved process for making Tl-Ca-Ba-CuO superconductors. A solution of the monocarboxylates (e.g., acetates) of Ca, Ba, and Cu is dried, calcined, mixed with Tl.sub.2 O.sub.3, and the mixture is heated to make a superconductor. The method minimizes introduction of contaminants. Novel compositions result.
    Type: Grant
    Filed: October 17, 1989
    Date of Patent: June 4, 1991
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Jacob Block, Leonard E. Dolhert
  • Patent number: 5017554
    Abstract: Compositions having the nominal formulaTl.sub.e Pb.sub.a Ca.sub.b Sr.sub.c Cu.sub.d O.sub.xwherein a is from about 1/10 to 3/2,b is from about 1 to 4,c is from about 1 to 3d is from about 1 to 5e is from about 3/10 to 1x=(a+b+c+d+e+y) where y is from about 1/2 to 3,are superconducting. Processes for manufacturing such compositions and for using them are disclosed.
    Type: Grant
    Filed: August 15, 1989
    Date of Patent: May 21, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Munirpallam A. Subramanian
  • Patent number: 5002926
    Abstract: Improved process for making Tl-Ca-Ba-Cu oxide superconductors. A solution of the nitrated of Ca, Ba, and Cu is reacted with a quaternary ammonium carbonate in a slurry (heel) of Tl.sub.2 O.sub.3. Carbonates of Ca, Ba, and Cu precipitate homogeneously on the Tl.sub.2 O.sub.3 particles. Solids are recovered, dried, and heated to make a superconductor. The method minimizes introdution of contaminants. Novel compositions result.
    Type: Grant
    Filed: June 3, 1988
    Date of Patent: March 26, 1991
    Assignee: W. R. Grace & Co.- Conn.
    Inventors: Nicholas D. Spencer, Leonard E. Dolhert
  • Patent number: 5001107
    Abstract: This invention provides improved methods for the preparation of precursor powders that are used in the preparation of superconducting ceramic materials that contain thallium. A first solution that contains the hydrogen peroxide and metal cations, other than thallium, that will be part of the ceramic is quickly mixed with a second solution that contains precipitating anions and thallium (I) to form a precipitate which is dried to yield precursor powders. The precursor powders are calcined an sintered to produce superconducting materials that contain thallium.
    Type: Grant
    Filed: August 2, 1989
    Date of Patent: March 19, 1991
    Assignee: The United States Department of Energy
    Inventors: Bruce C. Bunker, Diana L. Lamppa, James A. Voigt
  • Patent number: 4997811
    Abstract: A process of making high temperature Tl-based superconductors is disclosed. The process includes the steps of reacting solid Ba-Ca-Cu-oxides with Tl.sub.2 O.sub.3 vapor. The process allows high quality Tl-based superconductors to be easily fabricated.
    Type: Grant
    Filed: February 9, 1989
    Date of Patent: March 5, 1991
    Assignee: The University of Arkansas
    Inventors: Allen M. Hermann, Zhengzhi Sheng
  • Patent number: 4994432
    Abstract: A high temperature superconducting system has the general composition Tl-R-X-Y, wherein: R is a Group 2A element; X is a Group 1B element; and Y is a Group 6A element. Preferably, the composition has the following formula Tl-Ba-Cu-O. The high temperature superconductor of the present invention has a transition temperature of about 90 K with the probability of one phase superconducting at a temperature perhaps as high as 270 K. Processes for making the high temperature superconductor are also provided.
    Type: Grant
    Filed: January 15, 1988
    Date of Patent: February 19, 1991
    Assignee: University of Arkansas
    Inventors: Allen M. Hermann, Zhengzhi Sheng
  • Patent number: 4988668
    Abstract: Stable, bulk electrical superconductors are prepared by heating mixed metal oxides in the presence of oxygen in a closed vessel in a preheated oven for 1-5 hours at 850.degree.-900.degree. C. The final oxides are in the molar ratio Ti.sub.0.6-1.1 Ca.sub.2-3 Ba.sub.0.75-1.25 Cu.sub.2-3 O.sub.(5+.delta.)-(9+.delta.), where .delta. is less than one.
    Type: Grant
    Filed: March 22, 1989
    Date of Patent: January 29, 1991
    Assignee: International Business Machines Corporation
    Inventors: Edward M. Engler, Victor Y. Lee, Adel I. Nazzal, Stuart S. P. Parkin
  • Patent number: 4962083
    Abstract: A new high temperature superconductor with transition temperature above 120 K is disclosed. The superconductor in a preferred embodiment comprises T1RBaCuO wherein R is chosen from Group 2A elements excluding Ba. In another preferred embodiment, the superconductor comprises T1SrCuO. Processes for making high temperature superconductors are also disclosed.
    Type: Grant
    Filed: February 12, 1988
    Date of Patent: October 9, 1990
    Assignee: University of Arkansas
    Inventors: Allen M. Hermann, Zhengzhi Sheng
  • Patent number: 4929594
    Abstract: Compositions containing a crystalline phase of the formula Tl.sub.2 Ba.sub.2 CuO.sub.6+x wherein x is from 0 to 0.5. Processes for manufacturing such compositions and for using them are disclosed.
    Type: Grant
    Filed: March 14, 1988
    Date of Patent: May 29, 1990
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Jagannatha Gopalakrishnan, Munirpallam A. Subramanian