Ordered-defect structure in epitaxial YBa/sub 2/Cu/sub 3/O/sub 7/. sqrt. /sub x/ thin films

Journal Article · Wed Jun 01 00:00:00 EDT 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.37.9353· OSTI ID:5070679

Marshall, A F; Barton, R W; Char, K; Kapitulnik, A; Oh, B; Hammond, R H; Laderman, S S

An ordered defect structure in superconducting Y-Ba-Cu-O thin films has been characterized by both x-ray diffraction and transmission electron microscopy. The defect structure, which is observed growing epitaxially within the grains of normal YBa/sub 2/Cu/sub 3/O/sub 7/..sqrt../sub x/ structure, has the diffraction characteristics of a distinct phase whose volume fraction can be correlated with changes in film composition. The diffraction characteristics are consistent with an orthorhombic unit cell (a approx. =b = 3.86+A, c = 27.19 A) with space group Ammm. These are the characteristics to be expected from a structure in which extra copper-oxygen layers create fault planes, which are inserted at every unit cell in the parent YBa/sub 2/Cu/sub 3/O/sub 7/..sqrt../sub x/ structure. The composition expected for the pure phase is Y/sub 2/Ba/sub 4/Cu/sub 8/O/sub 20/..sqrt../sub x/. Preliminary transport measurements on films containing this extra phase are characterized by lower normal-state resistances and a lower Hall constant.

• Research Organization: Center for Materials Research, Stanford University, Stanford, California 94305
• OSTI ID: 5070679
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Vol. 37:16
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
CRYSTAL DEFECTS
COPPER OXIDES
YTTRIUM OXIDES
SUPERCONDUCTING FILMS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COHERENT SCATTERING
COPPER COMPOUNDS
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRON MICROSCOPY
FILMS
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
SCATTERING
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360202* - Ceramics
Cermets
& Refractories- Structure & Phase Studies