Dielectric and Raman investigations of structural phase transitions in (C2H5NH3)(2)CdCl4

Yadav, Ruchika and Swain, Diptikanta and Kundu, Partha P and Nair, Harikrishnan S and Narayana, Chandrabhas and Elizabeth, Suja (2015) Dielectric and Raman investigations of structural phase transitions in (C2H5NH3)(2)CdCl4. In: PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 17 (18). pp. 12207-12214.

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Abstract

Temperature-dependent Raman and dielectric measurements have been carried out on (C2H5NH3)(2)CdCl4 single crystals. Raman studies reveal the presence of two structural phase transitions below room temperature at 216 K and 114 K. The phase transitions are marked by anomalies in temperature dependence of wave-number and full width half maximum (FWHM) of several vibrational modes. The transitions are also accompanied by anomalies in dielectric measurements. Raman and dielectric data indicate that the transition at 216 K is order-disorder in nature and is driven by re-orientation of organic ions, while the transition at 114 K is due to coupling between the CdCl6 octahedron and the organic chain. Further high temperature dielectric measurements reveal the presence of one more structural phase transition around 473 K across which dispersion in dielectric parameters is observed. The activation energies and relaxation time obtained for high temperature dielectric phases are characteristic of combined reorientation motions of alkyl ammonium cations.

Item Type:	Journal Article
Publication:	PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Publisher:	ROYAL SOC CHEMISTRY
Additional Information:	Copy right for this article belongs to the ROYAL SOC CHEMISTRY, THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	15 Jun 2015 09:38
Last Modified:	15 Jun 2015 09:38
URI:	http://eprints.iisc.ac.in/id/eprint/51671

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