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Surface studies of YBa{sub 2}Cu{sub 3}O{sub 7-x} -matching oxide substrates and interfaces

Abstract

Crystallographic changes as a result of heat-treatment at 700-900 deg. C are found for SrTiO{sub 3}(100), MgO(100) and LaAlO{sub 3}(100). The p(2x2) reconstruction of the SrTiO{sub 3}(100) and the superstructures on MgO(100) and on LaAlO{sub 3}(100) thus observed are suggested to be induced by segregation of impurities to the surface. The surface charge-effects which disturb electron- and photon-impact experiments with these insulators are removed by heat-treatments. Deposition of copper results in formation of copper islands on SrTiO{sub 3}(100) and on LaAlO{sub 3}(100). Yttrium forms islands on LaAlO{sub 3}(100) and grows in a layer-by-layer mode on SrTiO{sub 3}(100) and on MgO(100). An yttrium 1x1 epitaxy is observed on the MgO(100) surface, which is suggested to be an YO superstructure. Oxidation of the 1x1 Y/MgO(100) systems diminishes the charge-effects and improves all diffraction and spectroscopic measurements. This may be due to the formation of metallic states around the Fermi level when the film is oxidized. An in situ synthesized YBa{sub 2}Cu{sub 3}O{sub 7} thin film on SrTiO{sub 3}(100) compared to a thick epitaxial YBa{sub 2}Cu{sub 3}O{sub 7-x}(001) film on MgO(100) reveals differences in surface electronic structures but not in surface stoichiometries. (au) 18 refs.
Publication Date:
Nov 01, 1990
Product Type:
Thesis/Dissertation
Report Number:
NEI-DK-794
Reference Number:
SCA: 360204; PA: AIX-23:038732; SN: 92000732458
Resource Relation:
Other Information: TH: Thesis (Ph.D.).; PBD: Nov 1990
Subject:
36 MATERIALS SCIENCE; SUPERCONDUCTING FILMS; ELECTRONIC STRUCTURE; SUBSTRATES; BARIUM OXIDES; COPPER OXIDES; CRYSTALLOGRAPHY; DEPOSITION; HIGH-TC SUPERCONDUCTORS; MICROELECTRONICS; SURFACES; SYNTHESIS; YTTRIUM OXIDES; 360204; PHYSICAL PROPERTIES
OSTI ID:
10142372
Research Organizations:
Copenhagen Univ. (Denmark). H.C. Oersted Inst.
Country of Origin:
Denmark
Language:
English
Other Identifying Numbers:
Other: ON: DE92627809; TRN: DK9200026038732
Availability:
OSTI; NTIS (US Sales Only); INIS
Submitting Site:
DKN
Size:
99 p.
Announcement Date:
Jul 05, 2005

Citation Formats

Enevold Thaulov Andersen, J. Surface studies of YBa{sub 2}Cu{sub 3}O{sub 7-x} -matching oxide substrates and interfaces. Denmark: N. p., 1990. Web.
Enevold Thaulov Andersen, J. Surface studies of YBa{sub 2}Cu{sub 3}O{sub 7-x} -matching oxide substrates and interfaces. Denmark.
Enevold Thaulov Andersen, J. 1990. "Surface studies of YBa{sub 2}Cu{sub 3}O{sub 7-x} -matching oxide substrates and interfaces." Denmark.
@misc{etde_10142372,
title = {Surface studies of YBa{sub 2}Cu{sub 3}O{sub 7-x} -matching oxide substrates and interfaces}
author = {Enevold Thaulov Andersen, J}
abstractNote = {Crystallographic changes as a result of heat-treatment at 700-900 deg. C are found for SrTiO{sub 3}(100), MgO(100) and LaAlO{sub 3}(100). The p(2x2) reconstruction of the SrTiO{sub 3}(100) and the superstructures on MgO(100) and on LaAlO{sub 3}(100) thus observed are suggested to be induced by segregation of impurities to the surface. The surface charge-effects which disturb electron- and photon-impact experiments with these insulators are removed by heat-treatments. Deposition of copper results in formation of copper islands on SrTiO{sub 3}(100) and on LaAlO{sub 3}(100). Yttrium forms islands on LaAlO{sub 3}(100) and grows in a layer-by-layer mode on SrTiO{sub 3}(100) and on MgO(100). An yttrium 1x1 epitaxy is observed on the MgO(100) surface, which is suggested to be an YO superstructure. Oxidation of the 1x1 Y/MgO(100) systems diminishes the charge-effects and improves all diffraction and spectroscopic measurements. This may be due to the formation of metallic states around the Fermi level when the film is oxidized. An in situ synthesized YBa{sub 2}Cu{sub 3}O{sub 7} thin film on SrTiO{sub 3}(100) compared to a thick epitaxial YBa{sub 2}Cu{sub 3}O{sub 7-x}(001) film on MgO(100) reveals differences in surface electronic structures but not in surface stoichiometries. (au) 18 refs.}
place = {Denmark}
year = {1990}
month = {Nov}
}