Effect of humidity on chemical stability and superconductivity of YBa sub 2 Cu sub 3 O sub 7 minus x

Journal Article · Sun Apr 01 04:00:00 EDT 1990 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.345345· OSTI ID:6924583

Naito, N; Kafalas, J; Jachim, L; Downey, M ^[1]

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1. GTE Laboratories Incorporated, Waltham, Massachusetts 02254 (USA)

The effect of relative humidity (0%, 40%, 51%, and 78%) on the stability of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} was investigated over a six-month period using x-ray diffraction, scanning electron microscopy, and magnetic susceptibility measurements. At 78% humidity, the fraction of superconductive phase decreased parabolically with time. After six months, the powders completely decomposed into BaCO{sub 3}, Y{sub 2}BaCuO{sub 5}, and CuO. Most of the samples placed at humidity levels of 51% or less were in the orthorhombic YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} phase at the end of six months and remained superconducting and stable. However, all powders kept at nonzero humidity levels were heavily agglomerated; some became hard solids with diameters equal to or greater than 0.1 mm. The microstructure of the powder indicated a surface reaction with water undetected by x-ray diffraction or magnetic susceptibility measurements.

• OSTI ID: 6924583
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 67:7; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AGGLOMERATION
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
CHEMICAL PROPERTIES
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRON MICROSCOPY
HUMIDITY
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
MICROSCOPY
MICROSTRUCTURE
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POWDERS
SCANNING ELECTRON MICROSCOPY
SCATTERING
STABILITY
SUPERCONDUCTORS
SURFACES
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION
YTTRIUM COMPOUNDS
YTTRIUM OXIDES