Accession Number : ADA299968
Title : Search for Higher Temperature Superconductors.
Descriptive Note : Final technical rept. 1 Jul 93-30 Jun 95,
Corporate Author : INTERNATIONAL BUSINESS MACHINES CORP SAN JOSE CA
Personal Author(s) : Torrance, Jerry B. ; Nazzal, Adel I.
PDF Url : ADA299968
Report Date : 10 OCT 1995
Pagination or Media Count : 14
Abstract : Using a special furnace capable of applying high oxygen partial pressures, samples of La(2-x)Sr(x)CuO(4-delta) were prepared. In this synthesis, oxygen partial pressures up to 15 Kbar thermodynamically favored the formation of higher valences of copper and correspondingly lower concentrations of oxygen vacancies. Large regions of phase separation were discovered at large x. Preparation conditions were modified in order to synthesize only single phase materials. Valences of copper up to Cu(+2.65) were achieved, compared with previous values of Cu(+2.35). Correspondingly, samples without oxygen vacancies were obtained up to x =0.65, almost doubling the range of potential superconducting copper oxides in this material system. Over the range of new compounds, 0.35(less than or equal to)X (less than or equal to)0.65, no superconductivity was observed above 7K. jg
Descriptors : *HIGH TEMPERATURE SUPERCONDUCTORS, *COPPER OXIDES, PREPARATION, SYNTHESIS, THERMODYNAMICS, HIGH PRESSURE, PHASE, OXYGEN, LOW LEVEL, CONCENTRATION(COMPOSITION), SEPARATION, VALENCE, STRONTIUM, LANTHANUM, FURNACES, PARTIAL PRESSURE.
Subject Categories : Inorganic Chemistry
Electricity and Magnetism
Distribution Statement : APPROVED FOR PUBLIC RELEASE