ISSN:
1600-5767
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Geosciences
,
Physics
Notes:
The lattice constants of hexagonal α-LiIO3 have been measured both by single-crystal neutron and X-ray diffractometry and by dilatometry in the range 20 to 520 K. The phase transition to γ-LiIO3 takes place at about 520 K. At 295 K, a = 5.48127(6) and c = 5.17165(4) Å for γ(Cu Kα1) = 1.540598 Å. The expansion is nonlinear and is fitted by the third-order polynomial aTi = a295i [1 + αiΔT + βi(ΔT)2 + γi(ΔT)3] with α1 = 25.3(3), α3 = 46.1(3) × 10−6 K−1, β1 = 23.0(8), β3 = 39(1) × 10−9 K−2, and γ1 = −25 (7), γ3 = −47(9) × 10−12 K−3, with ΔT = T−295 K. The principal thermal expansion coefficients aTi = a295i [1 + AiΔT + Bi(ΔT)2] increase monotonically with temperature, gradually approaching 32 × 10−6 K−1 for the a and 56 × 10−6 K−1 for the c axis from values at 20 K of 7.1 and 14.2 × 10−6 K−1, respectively.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0021889883010833
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