A new superconductor that displays onset behavior near 120 K has been identified as Bi(2)Sr(3-x)C... more A new superconductor that displays onset behavior near 120 K has been identified as Bi(2)Sr(3-x)Ca(x)Cu(2)O(8+y), with x ranging from about 0.4 to 0.9. Single crystal x-ray diffraction data were used to determine a pseudo-tetragonal structure based on an A-centered orthorhombic subcell with a = 5.399 A, b= 5.414A, and c = 30.904 A. The structure contains copper-oxygen sheets as in La(2)CuO(4) and YBa(2)Cu(3)O(7), but the copper-oxygen chains present in YBa(2)Cu(3)O(7) do not occur in Bi(2)Sr(3-x)Ca(x)Cu(2)O(8+y). The structure is made up of alternating double copper-oxygen sheets and double bismuth-oxygen sheets. There are Ca(2+) and Sr(2+) cations between the adjacent Cu-O sheets; Sr(2+) cations are also found between the Cu-O and Bi-O sheets. Electron microscopy studies show an incommensurate superstructure along the a axis that can be approximated by an increase of a factor of 5 over the subcell dimension. This superstructure is also observed by x-ray diffraction on single crysta...
There is now a new series of high temperature superconducting oxides that may be represented as A... more There is now a new series of high temperature superconducting oxides that may be represented as AâBâCa/sub n/minus/1/Cu/sub n/O/sub 2n+4/ where A/B = Bi/Sr or T1/Ba, and n, the number of CuOâ sheets stacked consecutively in the structure, equals 1, 2, or 3. There is a general trend toward higher superconducting transition temperatures as n increases. The preoperative conditions, superconducting
Crystals of the new high temperature superconductor Bi2Sr3-xCaxCu2O8+y have been grown and studie... more Crystals of the new high temperature superconductor Bi2Sr3-xCaxCu2O8+y have been grown and studied. Single crystal x-ray diffraction data were used to determine a pseudo tetragonal structure based on an A-centered orthorhombic cell with a = 5.399 Å, b = 5.414 Å, and c = 30.904 Å. The structure contains the copper-oxygen sheets as in La2CuO4 and YBa2Cu3O7, but the copper-oxygen
Nature is the international weekly journal of science: a magazine style journal that publishes fu... more Nature is the international weekly journal of science: a magazine style journal that publishes full-length research papers in all disciplines of science, as well as News and Views, reviews, news, features, commentaries, web focuses and more, covering all branches of science and ...
High values of proton conductivity have been observed in a class of hydrated metal oxide pyrochlo... more High values of proton conductivity have been observed in a class of hydrated metal oxide pyrochlores, HMOâ.xHâO (M = Sb, Nb, Ta). Two new polymorphs of HSbOâ.xHâO have been synthesized and are also found to be good proton conductors. One polymorph has a layer structure and is derived from KSbOâ with the ilmenite structure. The other new HSbOâ.xHâO polymorph has
A new superconductor that displays onset behavior near 120 K has been identified as Bi(2)Sr(3-x)C... more A new superconductor that displays onset behavior near 120 K has been identified as Bi(2)Sr(3-x)Ca(x)Cu(2)O(8+y), with x ranging from about 0.4 to 0.9. Single crystal x-ray diffraction data were used to determine a pseudo-tetragonal structure based on an A-centered orthorhombic subcell with a = 5.399 A, b= 5.414A, and c = 30.904 A. The structure contains copper-oxygen sheets as in La(2)CuO(4) and YBa(2)Cu(3)O(7), but the copper-oxygen chains present in YBa(2)Cu(3)O(7) do not occur in Bi(2)Sr(3-x)Ca(x)Cu(2)O(8+y). The structure is made up of alternating double copper-oxygen sheets and double bismuth-oxygen sheets. There are Ca(2+) and Sr(2+) cations between the adjacent Cu-O sheets; Sr(2+) cations are also found between the Cu-O and Bi-O sheets. Electron microscopy studies show an incommensurate superstructure along the a axis that can be approximated by an increase of a factor of 5 over the subcell dimension. This superstructure is also observed by x-ray diffraction on single crysta...
There is now a new series of high temperature superconducting oxides that may be represented as A... more There is now a new series of high temperature superconducting oxides that may be represented as AâBâCa/sub n/minus/1/Cu/sub n/O/sub 2n+4/ where A/B = Bi/Sr or T1/Ba, and n, the number of CuOâ sheets stacked consecutively in the structure, equals 1, 2, or 3. There is a general trend toward higher superconducting transition temperatures as n increases. The preoperative conditions, superconducting
Crystals of the new high temperature superconductor Bi2Sr3-xCaxCu2O8+y have been grown and studie... more Crystals of the new high temperature superconductor Bi2Sr3-xCaxCu2O8+y have been grown and studied. Single crystal x-ray diffraction data were used to determine a pseudo tetragonal structure based on an A-centered orthorhombic cell with a = 5.399 Å, b = 5.414 Å, and c = 30.904 Å. The structure contains the copper-oxygen sheets as in La2CuO4 and YBa2Cu3O7, but the copper-oxygen
Nature is the international weekly journal of science: a magazine style journal that publishes fu... more Nature is the international weekly journal of science: a magazine style journal that publishes full-length research papers in all disciplines of science, as well as News and Views, reviews, news, features, commentaries, web focuses and more, covering all branches of science and ...
High values of proton conductivity have been observed in a class of hydrated metal oxide pyrochlo... more High values of proton conductivity have been observed in a class of hydrated metal oxide pyrochlores, HMOâ.xHâO (M = Sb, Nb, Ta). Two new polymorphs of HSbOâ.xHâO have been synthesized and are also found to be good proton conductors. One polymorph has a layer structure and is derived from KSbOâ with the ilmenite structure. The other new HSbOâ.xHâO polymorph has
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