Buy article online - an online subscription or single-article purchase is required to access this article.
Download citation
Download citation
link to html
The d33 piezoelectric coefficient in sodium oxonium trihydroxotrioxoiodate (2-) is 4.3 ± 0.5 × 10-12 CN-1 at 298 K. The p3 pyroelectric coefficient is 4.3 ± 0.3 × 10-6 Cm-2 K-1 at 298 K, increasing to 14.5 × 10-6 Cm-2 K-1 at 220 K and becoming zero at about 137 K; p3 changes sign at lower temperatures. The absolute sense of the two coefficients at 298 K, determined with respect to the atomic arrangement, is given by d33>0, p3 <0. The Na+ ions are embedded within layers of I(OH)3O32- ions: the H3O+ ions are attached to these anion layers by strong hydrogen bonds. Compressive stress equivalent to finger pressure on a 1 mm2 crystal face displaces the Na+ ions toward the OH- surfaces and the H3O+ ions toward the O- surfaces of the anion layer by about 10-4 Å. An increase in temperature of 100 K displaces the positive ions in the same sense by about 2 × 10-3 Å. A similar model for elbaite tourmaline predicts an average cation displacement of 5-10 × 10-4 Å along the polar axis, on cooling the crystal through 100 K, consistent with the recent results of G. Donnay [Acta Cryst. (1977), A33, 927-932].

Subscribe to Journal of Applied Crystallography

The full text of this article is available to subscribers to the journal.

If you have already registered and are using a computer listed in your registration details, please email support@iucr.org for assistance.

Buy online

You may purchase this article in PDF and/or HTML formats. For purchasers in the European Community who do not have a VAT number, VAT will be added at the local rate. Payments to the IUCr are handled by WorldPay, who will accept payment by credit card in several currencies. To purchase the article, please complete the form below (fields marked * are required), and then click on `Continue'.
E-mail address* 
Repeat e-mail address* 
(for error checking) 

Format*   PDF (US $40)
In order for VAT to be shown for your country javascript needs to be enabled.

VAT number 
(non-UK EC countries only) 
Country* 
 

Terms and conditions of use
Contact us

Follow J. Appl. Cryst.
Sign up for e-alerts
Follow J. Appl. Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds