CATION SUBSTITUTION MODELS OF CONGRUENT LINBO3 INVESTIGATED BY X-RAY AND NEUTRON POWDER DIFFRACTION

被引：137

作者：

ZOTOV, N

BOYSEN, H

FREY, F

METZGER, T

BORN, E

机构：

[1] TECH UNIV MUNICH,D-85748 GARCHING,GERMANY

[2] BULGARIAN ACAD SCI,INST APPL MINERAL,BU-1000 SOFIA,BULGARIA

来源：

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS | 1994年 / 55卷 / 02期

关键词：

LITHIUM NIOBATE; DEFECT MODELS; X-RAY DIFFRACTION; NEUTRON DIFFRACTION; PHASE TRANSITION; DIFFUSE SCATTERING;

D O I：

10.1016/0022-3697(94)90071-X

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

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 square(4x)]NbO3 in which the Nb site is fully occupied describes best the average defect structure. The Nb-site vacancy model [Li1-5xNb5x][Nb(1-4x)square(4x)]O-3 and the Li split model [Li1-5x-yNbx square(4x+y)][Li-y]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.

引用

页码：145 / 152

页数：8

共 33 条

[1] FERROELECTRIC LITHIUM NIOBATE .5. POLYCRYSTAL X-RAY DIFFRACTION STUDY BETWEEN 24 DEGREES AND 1200 DEGREES C [J].