HRTEM, SAED and XRD investigations of La4O4[AsO 4]Br and Pr4O4[AsO4]Br

Hamdi Ben Yahia, Ute Ch Rodewald, Khalid Boulahya, José María Gonzalez-Calbet, Rainer Pöttgen

Research output: Contribution to journalArticle

5 Citations (Scopus)


The new oxide-bromide-oxoarsenates (V) La4O4[AsO 4]Br and Pr4O4[AsO4]Br were synthesised successfully by a solid state reaction route using a salt flux. Both compounds crystallise with a tetragonal cell. The twinned Pr4O 4[AsO4]Br structure was determined from single crystal X-ray diffraction data (P42/m, a = 834.91(9), c = 1321.6(2) pm, V = 0.9213 nm3 and Z = 4). It consists of alternating [Pr 4O4]4+ and [BrAsO4]4- layers. The [Pr4O4]+4 layer contains OPr 4/4 tetrahedra which share common edges. The AsO4 3- and Br- anions are located between these layers and form infinite chains along a at z = 0 and along b at z = 1/2. SAED and HRTEM experiments confirmed this well ordered structural model. X-ray powder diffraction data reveal isotypism of La4O4[AsO 4]Br: a = 843.07(1), c = 1355.28 pm, V = 0.9633 nm3.

Original languageEnglish
Pages (from-to)239-243
Number of pages5
JournalSolid State Sciences
Issue number1
Publication statusPublished - 1 Jan 2011


  • Arsenates (V)
  • Crystal chemistry
  • Merohedral twinning

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

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