Growth mechanisms of layered superconductors

Conference · Mon Jun 01 00:00:00 EDT 1992

OSTI ID:7116123

Pennycook, S J; Chisholm, M F; Jesson, D E; Feenstra, R; Zhu, S; Lowndes, D H

Using a combination of Z-contrast imaging, scanning tunneling microscopy, and plan view diffraction contrast imaging, we have studied the growth and relaxation mechanisms of YBa{sub 2}Cu{sub 3}O{sub 7-x} deposited on MgO and SrTiO{sub 3} substrates. Two-dimensional island growth occurs on SrTiO{sub 3} substrates, with relaxation through the nucleation of dislocation half-loops. Then the threading dislocation segments with a screw component can lead to kinetic roughening through the development of growth pyramids. In contrast, growth on MgO occurs by true one-dimensional island growth (with no wetting layer), most of the interface being incommensurate with the substrate (although crystallographically aligned). Dislocations with both edge and screw components are generated on island coalescence. A highly anisotropic surface energy is shown to responsible for cell-by-cell c{perpendicular} growth being thermodynamically preferred, although at high supersaturations a transition a{perpendicular} growth occurs.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 7116123
• Report Number(s): CONF-920402-48; ON: DE92018492
• Resource Relation: Conference: Material Research Society spring meeting, San Francisco, CA (United States), 27 Apr - 2 May 1992
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HIGH-TC SUPERCONDUCTORS
CRYSTAL GROWTH METHODS
ANISOTROPY
BARIUM OXIDES
COPPER OXIDES
CRYSTAL GROWTH
DISLOCATIONS
LAYERS
MAGNESIUM OXIDES
NUCLEATION
SCANNING ELECTRON MICROSCOPY
SUBSTRATES
SUPERLATTICES
SURFACE ENERGY
TITANIUM OXIDES
YTTRIUM OXIDES
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELECTRON MICROSCOPY
ENERGY
FREE ENERGY
LINE DEFECTS
MAGNESIUM COMPOUNDS
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SUPERCONDUCTORS
SURFACE PROPERTIES
THERMODYNAMIC PROPERTIES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication