Phase transformations in the Ca1-xSrxTiO3 perovskite system
Loading...
Date
2004-02-04
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Australian Institute of Physics
Abstract
The mixed perovskite Ca1-xSrxTiO3 is one of the major constituent phases of SYNROC, a synthetic rock form proposed for the long term immobilisation of high-level nuclear waste [1]. A complete understanding of the crystal structures formed, and transitions within, each of the constituent phases is of vital importance to gaining a complete knowledge of the overall structural stability of SYNROC. This study investigated the transition temperatures and the space group symmetry of several samples between the composition values of x = 0.6 to 0.85. Previous studies of this compound have produced many conflicting results. It is believed that the reason for this is the sample preparation technique coupled with the form of the sample during experimentation, i.e., powder vs. polycrystalline solid. This study has attempted to produce samples using techniques closely related to those used in bulk SYNROC manufacture and to analyse these samples in their polycrystalline form as they would exist in SYNROC. Transition temperatures were determined by observing the dynamic Young’s modulus and internal friction of the samples between 4K and 420K using the Piezoelectric Ultrasonic Composite Oscillator Technique [2]. Classifications of the crystal structures formed were carried out using the High Resolution Powder Diffractometer at the Lucas Heights Research Reactor within the temperature range of 8K to 300K. Space group symmetries for each phase were then determined by Rietveld refinement.
Description
Keywords
Phase transformations, Perovskite, Synthetic rocks, Radioactive wastes, Synthetic materials, Polycrystals, Piezometry, Pile oscillation techniques, Diffraction, ANSTO
Citation
Daniels, J. E., Elcombe, M. M., Finlayson, T. R., & Vance, E. R. (2004). Phase transformations in the Ca1-xSrxTiO3 perovskite system. Poster presented to the 28th Annual Condensed Matter and Materials Meeting, Charles Sturt University, Wagga Wagga, 3-6 February 2004. Retrieved from: https://www.physics.org.au/wp-content/uploads/cmm/2004/04handbook.pdf