title: Order-disorder of oxygen anions and vacancies in solid solutions of La2TiO5 and La4Ga2O9.
abstract: Successful Rietveld refinements of seven compounds with the formulae La2Ti((1-x))Ga(x)O((5-x/2)), where x = 0.00, 0.20, 0.50, 0.70, 0.90, 0.95 and 1.00, were performed in order to describe the solid solubility between orthorhombic (Pnam) La2TiO5 and monoclinic (P2(1)/c) La4Ga2O9. The relationship between the end-member structures, which are already known, is discussed; the space-group change is a consequence of ordering the oxygen vacancies that become more numerous as Ga is substituted for Ti. The structures of the solid solutions are also described. The lengths of cell edges obey Vegard's rule.
authors.affiliation: Faculty of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, 1000 Ljubljana, Slovenia.
authors.forename: Marta
authors.initials: M
authors.lastname: Kasunic
authors.forename: Anton
authors.initials: A
authors.lastname: Meden
authors.forename: Sreco D
authors.initials: SD
authors.lastname: Skapin
authors.forename: Danilo
authors.initials: D
authors.lastname: Suvorov
authors.forename: Amalija
authors.initials: A
authors.lastname: Golobic