Effect of oxygen distribution on the resistivity in YBa/sub 2/Cu/sub 3/O/sub 7-//sub delta/ oxides (0less than or equal todelta<0. 8)

Journal Article · Sat Oct 01 04:00:00 EDT 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.38.7087· OSTI ID:6824368

Yeh, N; Tu, K N; Park, S I; Tsuei, C C

The resistivity variation in ceramic YBa/sub 2/Cu/sub 3/O/sub 7-//sub delta/ (0less than or equal todelta<0.8) oxides has been studied as a function of delta during the oxygen in-diffusion and out-diffusion processes. The distribution of delta = delta(x,t) as a function of the position (x) and time (t) within a grain has been inferred for both processes. We conclude that the oxygen distribution in the oxides is inhomogeneous in the beginning of in-diffusion. This inhomogeneity is due to the fast saturation of oxygen (i.e., delta = 0) in the outer layer of each grain and the high activation energy of diffusion of oxygen through these superconducting ''shells'' (E = 1.3 +- 0.1 eV), which limit the rate of forming a uniform sample. The shell formation has important effects on the electronic properties of these superconducting oxides, and must be taken into account in attempting to control the oxygen homogeneity in these oxides, especially in single crystals. On the other hand, out-diffusion produces much more homogeneous samples of delta>0 due to a surface energy barrier E/sub out/ = 1.7 +- 0.1 eV.

• Research Organization: IBM Research Division, Thomas J. Watson Research Center, Yorktown Heights, New York 10598
• OSTI ID: 6824368
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 38:10; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204 -- Ceramics
Cermets
&amp; Refractories-- Physical Properties
656100* -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CORRELATIONS
CRYSTAL STRUCTURE
DIFFUSION
DISTRIBUTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
GRAIN SIZE
GRANULAR MATERIALS
MATERIALS
MICROSTRUCTURE
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SIZE
SUPERCONDUCTORS
TIME DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES