|About this Abstract
||MS&T23: Materials Science & Technology
||Phase Transformations in Ceramics: Science and Applications
||Crystal Structure Solution and Phase Transformations of CaZr4(PO4)6 and SrZr4(PO4)6
||Benjamin Hulbert, Julia Brodecki, Waltraud M. Kriven
|On-Site Speaker (Planned)
The NaZr2P3O12 (NZP) family of materials have shown promising low thermal expansion properties which can be tailored based on the ability to incorporate a wide range of cations in its structure. Novel high-temperature polymorphs of CaZr4(PO4)6 and SrZr4(PO4)6 were solved by Fourier difference mapping and Rietveld refinement. The phase transformation from R-3 to R-3c was measured on heating between 1100 and 1200 ℃ for both compositions. The thermal expansion of these materials was lowest at 25 ℃, then increased for all samples. SrZr4P6O24 shows greater anisotropy in thermal expansion in the high temperature R-3c phase than in the low temperature R-3 phase. This work provides new thermal expansion data from 500 to 1500 ℃ for all samples. Crystalline powder samples were synthesized using the organic-inorganic steric entrapment method. The samples were characterized with in-situ high temperature, x-ray diffraction at the APS (17-BM-B), from 25℃ to 1500 ℃.