Symmetry reduction and cation ordering in solid solution of stronium-lead and barium-lead nitrates
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Alexander G. Shtukenberg
Abstract
Kinetic ordering of the cations in (Sr,Pb)(NO3)2 and (Ba,Pb)(NO3)2 solid solutions with anomalous birefringence was studied by means of single crystal X-ray diffraction. The crystal structures of two samples of (Sr0.62Pb0.38)(NO3)2 and (Ba0.20Pb0.80)(NO3)2, respectively, taken from the {111} growth sectors as well as of two samples of (Sr0.62Pb0.38) (NO3)2 taken from the {100} growth sector were refined in the ideal structure space group Pa-3 and in two of its subgroups – trigonal R-3 and triclinic P-1 with R = 0.009 — 0.027. The final choice of trigonal symmetry for the samples from the {111} growth sectors is based on the analysis of the diffraction patterns and of the cation distributions over the crystallographic sites, which reflects the different orientations of the cation coordination polyhedra with respect to the (111) growth face (cubic setting). The observed optical indicatrices were successfully reproduced in the point-dipole approximation.
© Oldenbourg Wissenschaftsverlag
Articles in the same Issue
- Colorings of hyperbolic plane crystallographic patterns
- Structure determination without Fourier inversion. Part II: The use of intensity ratios and inequalities
- Symmetry reduction and cation ordering in solid solution of stronium-lead and barium-lead nitrates
- The crystal structures of polymorphic SUZ-4
- A crystallographic and spectroscopic study on the imine-amine tautomerism of 2-hydroxyaldimine compounds
Articles in the same Issue
- Colorings of hyperbolic plane crystallographic patterns
- Structure determination without Fourier inversion. Part II: The use of intensity ratios and inequalities
- Symmetry reduction and cation ordering in solid solution of stronium-lead and barium-lead nitrates
- The crystal structures of polymorphic SUZ-4
- A crystallographic and spectroscopic study on the imine-amine tautomerism of 2-hydroxyaldimine compounds
