Vibrational spectroscopic studies of phase transition in ferroelectric TAAP

Shashikala, M. N. ; Raghunatha Chary, B. ; Bhat, H. L. ; Narayanan, P. S. (1989) Vibrational spectroscopic studies of phase transition in ferroelectric TAAP Journal of Raman Spectroscopy, 20 (6). pp. 351-357. ISSN 0377-0486

Full text not available from this repository.

Official URL: http://onlinelibrary.wiley.com/doi/10.1002/jrs.125...

Related URL: http://dx.doi.org/10.1002/jrs.1250200603

Abstract

Tellurc acid ammonium phosphate (TAAP) is a new class m ferroelectric with a transition temperature of 45°C. Structural data and preliminary spectroscopic studies confirmed the presence of N-H...O hydrogen bonds. Raman spectroscopic studies on this crystal were carried out in the temperature range 20–80°C to look for possible spectral changes as a result of phase transition. A detailed analysis of the line width and frequencies was carried out across the phase transition in order to understand the nature of the phase transition. From the spectral features of the bands in different regions it is inferred that the groups TeO6, PO4 and NH4 do not undergo changes that could trigger the phase transition. On the other hand, the broadening of the bands in the range 2600–3400 cm-1 suggests the possibility of an order–disorder type of transition phenomenon involving hydrogen bonds. This is further supported by the shift of the transition temperature from 45 to 87°C on deuteration.

Item Type:Article
Source:Copyright of this article belongs to John Wiley and Sons.
ID Code:32344
Deposited On:29 Jun 2011 13:23
Last Modified:29 Jun 2011 13:23

Repository Staff Only: item control page