Accurate structural study of langasite-family Ca3TaGa3Si2O14 crystal

被引：16
作者：
Dudka, A. P. [1 ]
机构：
[1] Russian Acad Sci, AV Shubnikov Crystallog Inst, Leninskii Pr 59, Moscow 119333, Russia
来源：
CRYSTALLOGRAPHY REPORTS | 2016年 / 61卷 / 02期
基金：
俄罗斯基础研究基金会;
关键词：
STRUCTURE REFINEMENT; REDUCED DATA; X-RAY; LA3NB0.5GA5.5O14; DIFFRACTION; EXTINCTION; INCREASE; PROGRAM; GROWTH;
D O I：
10.1134/S1063774516020073
中图分类号：
O7 [晶体学];
学科分类号：
0702 ; 070205 ; 0703 ; 080501 ;
摘要：
An accurate X-ray diffraction study of Ca3TaGa3Si2O14 single crystal has been performed using two datasets obtained on a diffractometer equipped with a CCD area detector (a = 8.1056(2) , c = 4.9800(1) , sp. gr. P321, Z = 1, R/wR = 0.486/0.488%). A model structure is determined which is characterized by a high degree of reproducibility of structural parameters. Each site in Ca3TaGa3Si2O14 is occupied by atoms of only one type. Nevertheless, its structural feature is asymmetric disordering of sites of Ca, Ta, Ga, and two out of three oxygen atoms occupying special and general sites. A transition of some part of Ca atoms (similar to 3%) from 3e sites on the twofold symmetry axis to general 6g sites is revealed.
引用
收藏
页码：187 / 192
页数：6
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