Crystal chemistry of (RE,A)(2)M3O7 compounds (RE=Y, lanthanide; A=Ba, Sr, Ca; M=Al, Ga)

J M S Skakle, R Herd

Research output: Contribution to journalArticle

Abstract

Phases of general formula (RE,A)(2)M3O7 (RE=lanthanide, A=Ca, Sr, Pa; M=Ga, Al) are of interest for their nonlinear optical properties and have potential as solid state lasers. Their structures have been refined using X-ray and neutron diffraction data and are related to gehlenite, Ca2Al2SiO7, With M cations occupying Al and Si sites and RE and A cations sharing the Ca site with no evidence for ordering, although they occur in the ratio 1:1 because of stoichiometry; the M cations are tetrahedrally coordinated. (RE,Ba)(2)M3O7 compounds cannot be synthesized for M=Al or for RE cations smaller than Sm; this limitation is believed to be due to size mismatch between cations within the structure. (C) 1999 International Centre for Diffraction Data. [S0885-7156(99)00501-1].

Original languageEnglish
Pages (from-to)195-202
Number of pages8
JournalPowder Diffraction
Volume14
Publication statusPublished - 1999

Keywords

  • Rietveld refinement
  • optical materials
  • rare earths
  • gehlenite
  • neutron diffraction
  • PEROVSKITE-TYPE OXIDE
  • SRLAGA3O7
  • CA2GA2SIO7

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