Structural studies on Li 1−xTa 3O 8−xF x solid solutions by full-profile refinements of guinier-hägg X-ray film data

Abstract

Three compositions of solid solutions Li 1−xTa 3O 8−xF x (x = 0) 0.25 and 0.5) have been studied by full-profile analysis of microdensitometer-measured Guinier-Hägg powder diffraction data. From sequential changes in disorder and interatomic distances within this series, the preferred lithium position is proposed to be approximately (0.11, 1 2 , 0.03). The results obtained for the high temperature modification of LiTa 3O 8 by A.G. Nord and J.O. Thomas from X-ray single crystal and neutron powder diffraction data [Nord, A.G. and Thomas, J.O., Acta Chem. Scand., in press] are discussed in view of the present investigation.