New superionic and high temperature superconducting oxides: A sub 2 O-P sub 2 O sub 5 -SiO sub 2 (A = H,Li,Na,K) sol-gel ionic conductors, Ln-Ba-Cu-O (Ln = Y, rare earth) and Tl sub 2 Ba sub 2 minus x Sr sub x CaCu sub 2 O sub 8 superconductors
Glasses in the A{sub 2}O-P{sub 2}O{sub 5}-SiO{sub 2} (A = H, Li, Na, K) system were prepared by the sol-gel technique. Ionic conductivity, thermal analysis, SEM, EDX, FTIR data and phase diagram information are reported. Monolithic xerogel specimens form only with high silica content. The best conductivities observed include 8 x 10{sup {minus}5} ({Omega}-cm){sup {minus}1} at 573 K for 0.20Li{sub 2}O-0.20P{sub 2}O{sub 5}-0.60SiO{sub 2}{sm bullet}Li{sub 2}O-P{sub 2}O{sub 5}-SiO{sub 2} and P{sub 2}O{sub 5}-SiO{sub 2} samples immersed in molten LiCl were found to be highly hygroscopic and have room temperature proton conductivities {approx}10{sup {minus}2} ({Omega}-cm){sup {minus}1}. Superconductivity was observed around 90 K in the mixed and single phase systems Ln-Ba-Cu-O (Ln = Y, Ho, Er). X-ray powder diffraction, A.C. susceptibility and resistivity data are reported. Low temperature heat capacity measurements were made for Ln = Y, Sm, Gd, Ho, Er. The orthorhombic to tetragonal phase transition was studied in the solid solutions Eu{sub 1+x}Ba{sub 2{minus}x}Cu{sub 3}O{sub 7+{delta}} by X-ray powder diffraction, resistivity and TGA. The structural transition occurs at x = 0.2. {Tc} was found to decrease with increasing x while {delta} was found to increase. Magnetic and electrical properties were studied in YBa{sub 2}Cu{sub 3}O{sub 7} sol-gel prepared samples. Critical current was found to be the highest in the sol-gel prepared samples when compared to samples prepared by solid state reaction or the amorphous citrate co-precipitation process. Tl{sub 2}Ba{sub 2{minus}x}Sr{sub x}CaCu{sub 2}O{sub 8} solid solutions were prepared and characterized by resistivity and magnetic susceptibility measurements.
- Research Organization:
- Rutgers-the State Univ., New Brunswick, NJ (USA)
- OSTI ID:
- 6071718
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BARIUM OXIDES
IONIC CONDUCTIVITY
PHASE DIAGRAMS
SUPERCONDUCTIVITY
CALCIUM OXIDES
COPPER OXIDES
ERBIUM OXIDES
HOLMIUM OXIDES
LITHIUM OXIDES
PHOSPHORUS OXIDES
POTASSIUM OXIDES
SILICON OXIDES
SODIUM OXIDES
STRONTIUM OXIDES
THALLIUM OXIDES
YTTRIUM OXIDES
AMBIENT TEMPERATURE
CRYSTAL-PHASE TRANSFORMATIONS
GLASS
MAGNETIC SUSCEPTIBILITY
SCANNING ELECTRON MICROSCOPY
SOL-GEL PROCESS
SPECIFIC HEAT
TRANSITION TEMPERATURE
X-RAY DIFFRACTION
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
COHERENT SCATTERING
COPPER COMPOUNDS
DIAGRAMS
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
ERBIUM COMPOUNDS
HOLMIUM COMPOUNDS
LITHIUM COMPOUNDS
MAGNETIC PROPERTIES
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHOSPHORUS COMPOUNDS
PHYSICAL PROPERTIES
POTASSIUM COMPOUNDS
RARE EARTH COMPOUNDS
SCATTERING
SILICON COMPOUNDS
SODIUM COMPOUNDS
STRONTIUM COMPOUNDS
THALLIUM COMPOUNDS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties
360202 - Ceramics
Cermets
& Refractories- Structure & Phase Studies
360603 - Materials- Properties
656100 - Condensed Matter Physics- Superconductivity