Mischkristallbildung in den Systemen As2O5/SbAsO5 und As2O5/AsPO5 Bestimmung der spontanen Deformationen und Verfeinerung der Kristallstrukturen der ternären Randphasen

Formation of Solid Solutions within the Systems As₂O₅/SbAsO₅ and As₂O₅/AsPO₅ Determinations of the Spontaneous Deformations and Refinements of the Crystal Structures of the Ternary Border Phases As₂O₅ allows for substitution of tetrahedrally and octahedrally coordinated arsenic by phosphours and antimony, respectively. The solid solutions As_{2? x}P_xO₅ and Sb_xAs_{2? x}O₅ range from x = 0.5 to 1.0 and x = 0.75 to 1.0. The crystal structures of the ternary oxides AsPO₅ and SbAsO₅ have been refined by profile fitting of x-ray powder diagrams; both are isostructural to As₂O₅, for lattice constants see ?Inhaltsübersicht”?. Both are undergoing ferroelastic/paraelastic phase transitions which are completed at 600°C (AsPO₅) and 760°C (SbAsO₅), the spontaneous strains at room temperature being ?_s = 1.50 × 10^?2 and 2.27 × 10^?2 respectively.