The structures of sodium niobate between 480° and 575°C, and their relevance to soft-phonon modes
- 1 October 1972
- journal article
- research article
- Published by Taylor & Francis Ltd in Philosophical Magazine
- Vol. 26 (4), 995-1014
- https://doi.org/10.1080/14786437208226972
Abstract
The structures of NaNb03 in the S phase (480°-520°c) and T1 phase (520°-575°c) have been determined by use of the octahedron tilting schemes of Glazer. Both phases are orthorhombic with unit cell edges approximately twice those of ideal perovskite; their space groups are Pnmm and Ccmm, respectively. An explanation of the T2 to T1 (575°c) transition is given in terms of a soft phonon mode at q = 1/2 1/2 1/2 A comparison is made with the low-temperature transitions in KMnF3.This publication has 11 references indexed in Scilit:
- The structure of sodium niobate (T2) at 600°C, and the cubic-tetragonal transition in relation to soft-phonon modesPhilosophical Magazine, 1972
- N. M. R. STUDY OF PHASE TRANSITIONS IN PEROVSKITES CRYSTALSLe Journal de Physique Colloques, 1972
- X-ray diffuse scattering from NaNbO3as a function of temperatureActa Crystallographica Section A, 1971
- Diffuse X-Ray Study of 640°C Phase Transition in NaNbO3Journal of the Physics Society Japan, 1971
- Neutron scattering study of the lattice dynamical phase transitions in KMnF3Solid State Communications, 1970
- The structure of sodium niobate at room temperature, and the problem of reliability in pseudosymmetric structuresActa Crystallographica Section B: Structural Science, Crystal Engineering and Materials, 1969
- The thermal expansion of interatomic bonds, illustrated by experimental evidence from certain niobatesActa Crystallographica Section A Foundations and Advances, 1968
- The high-temperature phases of sodium niobate and the nature of transitions in pseudosymmetric structuresActa Crystallographica, 1966
- Magnetic Properties of KMn. I. Crystallographic StudiesPhysical Review B, 1961
- Crystal stability and the theory of ferroelectricityAdvances in Physics, 1960