Contents lists available at ScienceDirect Physica E: Low-dimensional Systems and Nanostructures journal homepage: www.elsevier.com/locate/physe Spectroscopic, dielectric properties and phase transition of Bis (diethylammonium) hexachlorido stannate(IV) Sahel Karoui a,* , Hassen Chouaib a,b , Slaheddine Kamoun a a Laboratory of Material Engineering and Environment (LR11ES46), National School of Engineering, Box 1173, 3038, Sfax, Tunisia b Physics Department, Faculty of Sciences and Arts-Tabarjal, Jouf University. P. O. Box 2014, Jouf, Skaka, 42421, Saudi Arabia ARTICLE INFO Keywords: X-ray powder Raman Dielectric properties Impedance spectroscopy AC conductivities Conduction mechanism ABSTRACT The [C 4 H 10 NH 2 ] 2 SnCl 6 compound is characterized by using the X-ray powder analysis, thermogravimetric analysis, differential scanning calorimetry analysis, 13 C and 119 Sn (CP/MAS NMR) analysis, vibrational spec- troscopy and complex impedance spectroscopic data. The results show that this compound exhibits a phase transition at 326 K which was characterized by differential scanning calorimetry (DSC), X-rays powder dif- fraction, Raman spectroscopy and dielectric measurements. The most important changes are observed for four lines at 3207 cm -1 , 3056 cm -1 , 3000 cm -1 and 1538 cm -1 (at room temperature) issued from asymmetric and symmetric stretching vibrations of ν s (NH 2 ), ν s (NH 2 ), ν as (NH 2 ) and ν δ (NH 2 ) band, respectively. The assignment of the observed IR and Raman lines was performed by comparison with the homologous compounds. Dielectric data were analyzed using complex permittivity ε* and complex electrical modulus M* for the sample at various temperatures. The Z′ and Z” versus frequency plots are well fitted to an equivalent circuit model. The analysis of Nyquist plots are well fitted to an equivalent circuit consisting of series of combination of grains and grain boundary elements. The AC conductivity was studied using the following equation: = + + + ∞ + σ ω Aω ( ) AC σs τω σ τω τω s 1 22 22 1 22 . The conductivity follows the Arrhenius relation. Hopping frequency was de- termined and activation energy of hopping is almost equal to the activation energy of conduction. The tem- perature dependence of the power law exponent s and a.c conductivity σ ac is reasonably interpreted by the quantum mechanical tunneling (QMT) and the barrier hopping (CBH) model. The modulus plot can be char- acterized by full width at half height or in terms of a non-experiential decay function ϕ(t) = exp(-t/τ)β. 1. Introduction This work is a part of our study of the new functional materials of alkyldiammonium metal halogenides. In this system, halogenostannate hybrid compounds are frequently characterized by their specific phy- sical and chemical properties, like magnetic or ferroelectric transitions, conductivity (superconductivity), photoluminescence and electro- luminescence [1–8], which could lead to technological innovations. A number of alkylammonium halogenostannate of different stoichiometry exhibit interesting sequences of phase transitions connected with changes in molecular dynamics of the cation sublattice. Many of these salts reveal ferroelectric or pyroelectric properties related to the order- disorder phase transitions. Moreover, these materials may be used as model compounds for ferroelectric and ferroelastic applications [9,10]. In general, these compounds of formula (R–NH 2 –R) 2 SnX 6 consist of a complex halogenostannate anion and an organic cation [11–13]. As an extension of our previous studies on hybrid organic halogenostannates materials [14–16], a hybrid compound with the formula [C 2 H 5 NH 2 ] 2 SnCl 6 has been synthesized. Many of these compounds ex- hibit structural phase transitions, which are associated with the reor- ientational dynamics of the ammonium group and the hopping me- chanism, dominated by the motion of the H + ions via the hydrogen bonds [15]. The present paper is devoted to investigate magic-angle spinning nuclear magnetic resonance (MAS-NMR), the vibrational (in- frared and Raman), the optical (absorption) properties, the dynamics by Raman scattering, DSC and X-ray powder diffraction patterns, the ionic transport and relaxation properties of the [C 4 H 10 NH 2 ] 2 SnCl 6 compound in the temperature range from 300 to 363 K. For this purpose, the electrical impedance measurements, temperature and frequency de- pendence of the dielectric proprieties of the compound is studied. 2. Experimental The Bis(diethylammonium) hexachlorido stannate(IV) were https://doi.org/10.1016/j.physe.2019.113596 Received 14 February 2019; Received in revised form 6 May 2019; Accepted 10 June 2019 * Corresponding author. E-mail address: karouisahel@yahoo.fr (S. Karoui). Physica E: Low-dimensional Systems and Nanostructures 114 (2019) 113596 Available online 23 June 2019 1386-9477/ © 2019 Elsevier B.V. All rights reserved. T