Synthesis and characterization of oxysulfides and high- Tc superconductors

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:6110255

Tao, Yuan K'ai

The first part of this dissertation discusses the use of hydrothermal reactions and vapor phase transport methods to synthesize antimony oxysulfide (Sb{sub 2}OS{sub 2} or Sb{sub 2}O{sub 2}S), and the use of radio frequency sputtering techniques to synthesize molybdenum oxysulfide. Although oxysulfides could not be prepared, two new phases were identified in the products from the hydrothermal reactions: a new form of antimony sulfide. In the second part of this work the effect of the substitution of various metallic elements for each cation in the superconducting compound YBa{sub 2}Cu{sub 3}O{sub 6+{delta}} was studied with the expectation that clues might be obtained that will shed light on the mechanism responsible for high-{Tc} superconductivity. The final part of this work concentrated on the phase diagram study of the Bi-Sr-Ca-Cu-O system between 800C to 880C because the new high-{Tc} compounds occur here. The results of this study showed that the best phase-pure material exhibiting {Tc} = 80 K was obtained from an initial mixture of 4Bi:3Sr:3Ca:4Cu. This phase has the stoichiometry Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} as published in the literature. The second phase was obtained from an initial mixture of 1Bi:1Sr:1Cu. The powder diffraction pattern and single-crystal X-ray photographs agree with the lattice constants reported for Bi{sub 2}Sr{sub 2}CuO{sub 6}, {Tc} = 7K.

• Research Organization: Texas Univ., Austin, TX (USA)
• OSTI ID: 6110255
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANTIMONY SULFIDES
CHEMICAL PREPARATION
COPPER OXIDES
ELECTRONIC STRUCTURE
PHASE STUDIES
HIGH-TC SUPERCONDUCTORS
MOLYBDENUM SULFIDES
SPUTTERING
BISMUTH OXIDES
CALCIUM OXIDES
CRYSTAL STRUCTURE
LATTICE PARAMETERS
OXYSULFIDES
STRONTIUM OXIDES
VERY HIGH TEMPERATURE
ALKALINE EARTH METAL COMPOUNDS
ANTIMONY COMPOUNDS
BISMUTH COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
MOLYBDENUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METAL COMPOUNDS
STRONTIUM COMPOUNDS
SULFIDES
SULFUR COMPOUNDS
SUPERCONDUCTORS
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
360601* - Other Materials- Preparation & Manufacture
360202 - Ceramics
Cermets
& Refractories- Structure & Phase Studies
360204 - Ceramics
Cermets
& Refractories- Physical Properties
656100 - Condensed Matter Physics- Superconductivity