title: Raman scattering investigation of the high temperature phase transition in [N(C3H7)4]2SnCl6.
abstract: The phase transition at high temperature of bis-tetrapropylammoniumhexachlorostannate compound has been investigated by Raman spectroscopy as a function of temperature from 303 K to 393 K. While the bands mainly associated with the internal modes of the SnCl6 anions only undergo weak changes, strong evolutions of wavenumbers, widths and intensities of many lines associated with the organic cations are observed with discontinuities in the vicinity of the phase transition at 362 K. The most important changes are observed for two lines at 1137.5 cm(-1) and 1159.4 cm(-1) (at room temperature) issued from twisting of CH2 groups and skeletal deformation of the cations. The spectral characteristics of these lines are analyzed and consistently described in the framework of an order-disorder model for the phase transition. The temperature dependency of the reduced peak intensity allowed to determine the critical exponents and evolution of the correlation length on approaching the transition.
authors.affiliation: Unité de recherche de la matière condensée, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax, Tunisia. Electronic address: hajlaouisondes@yahoo.fr.
authors.forename: Sondes
authors.initials: S
authors.lastname: Hajlaoui
authors.affiliation: Unité de recherche de la matière condensée, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax, Tunisia.
authors.forename: Iskandar
authors.initials: I
authors.lastname: Chaabane
authors.affiliation: Unité de recherche de la matière condensée, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax, Tunisia.
authors.forename: Abderrazak
authors.initials: A
authors.lastname: Oueslati
authors.affiliation: Unité de recherche de la matière condensée, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax, Tunisia.
authors.forename: Kamel
authors.initials: K
authors.lastname: Guidara
authors.affiliation: LUNAM Université, Université du Maine, CNRS UMR 6283, Institut des Molécules et Matériaux du Mans (IMMM), Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Bulou
mesh_terms: D006358:Hot Temperature; D009947:Organotin Compounds / Q000737:chemistry*; D044367:Phase Transition; D013059:Spectrum Analysis, Raman / Q000379:methods*; D044366:Transition Temperature
chemical_list: D009947:Organotin Compounds; C000600063:bis-tetrapropylammoniumhaxachlorostannate
keywords: Bis-tetrapropylammoniumhaxachlorostannate; Order–disorder; Phase transition; Raman scattering; Reduced Raman intensity