Zotov, N.; Boysen, Hans; Frey, Friedrich; Metzger, T.; Born, E.
Cation substitution models of congruent LiNbO3 investigated by X-ray and neutron powder diffraction.
In: Journal of Physics and Chemistry of Solids, Vol. 55, No. 2: pp. 145-152
Full text not available from 'Open Access LMU'.
The average structure of congruent lithium niobate has been reexamined by X-ray and neutron powder diffraction. The Rietveld refinements show that the Li-site vacancy model [Li1 - 5xNbx□4x]NbO3 in which the Nb site is fully occupied describes best the average defect structure. The Nb-site vacancy model [Li1 - 5x Nb5x][Nb1 - 4x □4x]O3 and the Li split model [Li1 - 5x - yNbx □4x + y][Liy]NbO3 can be definitely rejected. Several Nb split models in which the excess Nb atoms are distributed among the Li and the vacant cation sites, however, are also possible. The necessity of combined X-ray and neutron refinements is pointed out.