ISSN:
1600-5767
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Geosciences
,
Physics
Notes:
The absolute sense of a large single-crystal of Ba(NO2)2.H2O (point group 6), and of one of Cs2S2O6 (point group 6mm), was determined by use of X-ray anomalous scattering methods. The piezoelectric d33 and pyroelectric p3 coefficients were measured on the same crystals, thereby leading to the assignment of the absolute sense of both coefficients. The magnitudes and senses found for Ba(NO2)2.H2O at 298 K are p3 = −14 (1) × 10−5 C m−2 K−1 and d33 = +3.1 (2) × 10−12 C N−1. The absolute coefficients for Cs2S2O6 at 298 K are p3 = +0.9 (2) × 10−6 C m−2 K−1 and d33 = + 14.7 (1.0) x 10−12 C N−1. The atomic displacements in Ba(NO2)2.H2O corresponding to p3 are 5.7 × 10−4 Å K−1 by the Ba2+ ion or dipolar rotations of 7.7 arc min K−1 by NO2 or H2O: for d33, the displacements are about 0.1 × 10−4 Å (106 N m−2)−1 by Ba2+ or dipolar rotations of 0.2 arc min(106 N m−2)−1. In the case of Cs2S2O6, the Cs+ ion displacements are 0.1 × 10−4 Å K−1 on heating and 0.2 × 10−3 Å (106 N m−2)−1 under stress. Dipolar rotations do not contribute either to p3 or to d33 in Cs2S2O6.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0021889880012691
