Publication
Title
Crystal-structure of the double-hg-layer copper-oxide superconductor $(Hg,Pr)_{2}Ba_{2}(Y,Ca)Cu_{2}O_{8-\delta}$as a function of doping
Author
Abstract
 The crystal structure of the newly discovered double-Hg-layer copper oxide superconductor (Hg, Pr)(2)Ba-2(Y, Ca)Cu2O8-delta was studied as a function of chemical doping using neutron and electron diffraction and high-resolution transmission electron microscopy (HREM). Rietveld refinements of the structural parameters from neutron powder diffraction data indicate that the oxygen site O3 on the mercury plane is highly defective, being both partially occupied and displaced from the high-symmetry position. The variable concentration of oxygen vacancies partially compensates for the cation doping and, together with the O3 displacement field, makes some of the Hg atoms acquire an unusual pyramidal coordination. HREM images confirm that the structure is of the '2212' type, with very few defects. In some grains, faint superstructure reflections were evidenced by electron diffraction, suggesting that both the oxygen vacancies and the O3 displacement field may order at least on a local scale.
Language
English
Source (journal)
The journal of physics and chemistry of solids. - New York, N.Y.
Publication
New York, N.Y. : 1995
ISSN
0022-3697
Volume/pages
56:10(1995), p. 1471-1478
ISI
A1995RR95600025
Full text (Publisher's DOI)
Full text (publisher's version - intranet only)
UAntwerpen
 Faculty/Department Research group Publication type Subject Affiliation Publications with a UAntwerp address