Srinivasan, MR and Rama Rao, AH and Shabanova, LA and Bhat, HL and Narayanan, PS (1978) Studies on the phase transitions in thiourea. In: Ferroelectrics, 21 (1-4). 539-541 .
Full text not available from this repository. (Request a copy)Abstract
Thiourea (CS(NH2)2) is one of the few examples of molecular crystals exhibiting ferroelectric properties. The dielectric constant along the ferroelectric axis [100] shows maxima at 169, 177 and 202 K. An inflection point occurs at 170.5 KZ Following Goldsmith and White the phases are named as I (F.E. below 169 K), II (A.F.E. 169 K<T<176 K), I11 (F.E. 176 K<T<180 K), IV (A.F.E. 180 K<T<202 K) and V (P.E. Above 202 K). The appearance of satellite spots in the x-ray and neutron scattering indicates the presence of structural modulation in phases 11, 111 and IV.4,5 The effect of structural modulation is to destroy the local n glide symmetry, though the overall structure is Pnma. Thiourea also exhibits thermoluminescence after being irradiated with x-rays which is accounted for by defects like NH3+ and NH- formed by the breaking of hydrogen bonds.
| Item Type: | Journal Article |
|---|---|
| Publication: | Ferroelectrics |
| Publisher: | Taylor and Francis Group |
| Additional Information: | Copyright of this article belongs to Taylor and Francis Group. |
| Department/Centre: | Division of Physical & Mathematical Sciences > Physics |
| Date Deposited: | 24 Sep 2010 07:19 |
| Last Modified: | 24 Sep 2010 07:19 |
| URI: | http://eprints.iisc.ac.in/id/eprint/32433 |
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