EXAFS data resolved into individual site occupation preferences in quaternary compounds with tetrahedral coordinated structure

B.V. Robouch, A. Kisiel

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12 Citations (Scopus)

Abstract

Site-occupation preferences (SOPs) in quaternary GaxIn1-xAsySb1-yand Cd1-xMnxSeyTe1-ycompounds in tetrahedrally coordinated (T-C) zinc blende (ZB) structures are discussed, where x and y are the relative contents of cations and anions, respectively. A probabilistic approach defines individual component pair-populations from measured average-pair distributions. Particular attention is paid to the T-C ZB-structure. The methodology and interpretation of SOPs of published extended X-ray absorption fine structure (EXAFS) experimental data for overall average-pair distributions are discussed. The approach allows definition of component individual Tk-pair site-occupation populations and deeper insight into the selective processes that cause individual pair preferences in semiconducting multinary compounds. EXAFS-reported departures from Bernoulli random distributions point to changes within elemental tetrahedral average populations. Resolution requires that for T-C-structures, experimental data best fit be a 4th degree polynomial, the product of a parabola times the factor x(1-x). Analysis shows that GaInAsSb and CdMnSeTe have a marked preference for elemental tetrahedra with odd numbers of competing species of ions around a central ion, and that the former exhibits SOPs of 2.19±0.2 and 1.64±0.11 for elemental tetrahedra with respectively 1 and 3 Ga-ions around As-ions, and the latter, a SOP of 1.9±0.11 for 1Mn3Cd-ions around Se-ion configurations, with respect to the random case.
Original languageEnglish
Pages (from-to)80 - 88
Number of pages9
JournalJournal of Alloys and Compounds
Volume286
Issue number1-2
DOIs
Publication statusPublished - 5 May 1999
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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