Strong anisotropic thermal expansion in cristobalite-type BPO{sub 4}
- Applied Chemistry Division, Solid State Chemistry Section, Bhabha Atomic Research Centre, Mumbai 400 085, Maharashtra (India)
In this communication, the thermal expansion behavior of cristobalite-type BPO{sub 4}, determined from high-temperature X-ray diffraction studies, is being reported. BPO{sub 4} crystallizes in tetragonal lattice, with space group I-4 (No. 82) at room temperature, with unit cell parameters: a=4.3447(2), c=6.6415(5) A and V=125.37(1) A{sup 3}. The tetragonal unit cell parameters at 900 deg. C are: a=4.3939(2), c=6.6539(6) A and V=128.46(1) A{sup 3}. The results show a very strong anisotropic expansion in the lattice, with the typical thermal expansion coefficients along a- and c-axis 12.9x10{sup -6} and 2.1x10{sup -6}/ deg. C, respectively. The volume thermal expansion coefficient of the lattice is 28.2x10{sup -6}/ deg. C in the temperature range of 25-900 deg. C. The variation of the crystal structure with temperature and the thermal expansion behavior are explained in this manuscript. The role of inter-polyhedral angle on the thermal expansion behavior has also been established.
- OSTI ID:
- 20658169
- Journal Information:
- Journal of Solid State Chemistry, Vol. 177, Issue 11; Other Information: DOI: 10.1016/j.jssc.2004.07.036; PII: S0022-4596(04)00396-2; Copyright (c) 2004 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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