Verschiedene Aspekte der Kristallstrukturen von YbV4O8. 1 III. Domänenstruktur aus parallel verwachsenen Bereichen der α-und β-Phasen und gruppentheoretische Betrachtung ihrer Symmetrie

Abstract

Abstract The crystal structure of a multiple domain crystal of composition YbV4O8 has been determined and refined as a commensurate composite crystal with two subsystems. Subsystem 1 is formed by the V2O4 atoms, subsystem 2 contains the Yb atoms. All reflections in the diffraction pattern can be indexed using a lattice with a = 9.057(1) Å, b = 21.238(5) Å and c = 5.7560(9) Å yet three different types of domains have to be taken into account to explain the diffraction pattern. Domains I and II correspond to two twin domains of β-YbV4O8 with symmetry A21/d11 (≡ P21/n11) while domain III with symmetry P121/n1 has the structure of α-YbV4O8. Refinement was carried out in higher dimensional space using the reflections of all domains simultaneously and converged at a final R(F) value of 0.050 (Rw (F) = 0.038). The results are discussed.