Thermal and structural properties, and molecular dynamics in organic-inorganic hybrid perovskite (C2H5NH3)2ZnCl4.

Ae Ran Lim

doi:10.1039/c9ra07695f

Abstract

The thermal and structural properties and molecular dynamics of layered perovskite-type (C2H5NH3)2ZnCl4 are investigated by differential scanning calorimetry, thermogravimetric analysis, and magic angle spinning nuclear magnetic resonance spectroscopy. The thermal properties and phase transitions are studied. Additionally, the Bloembergen–Purcell–Pound (BPP) curves for the 1H spin–lattice relaxation time T1ρ in the C2H5NH3 cation and for the 13C T1ρ in C2H5 are shown to have minima as a function of inverse temperature. This observation implies that these curves represent the rotational motions of 1H and 13C in the C2H5NH3 cation. The activation energies for 1H and 13C in the C2H5NH3 cation are obtained; the molecular motion of 1H is enhanced at the C-end and N-end of the organic cation, and that at the carbons of the main chain is not as free as that for protons at the C-end and N-end.

Highlights

Hybrid organic–inorganic compounds allow for the possibility of combining the properties of organic and inorganic materials at the molecular level.[1,2,3,4] This class of hybrid materials is very broad and offers a wide set of different structures, properties, and potential applications.[5,6,7,8,9,10,11,12] A new type of layered perovskite multiferroic, (C2H5NH3)2CuCl4, as a metal organic compound was found by Kundys et al.[6]
Multiferroics refer to materials that simultaneously have two or more of the following properties: spontaneous ferroelectricity, ferromagnetism, or ferroelasticity.[13] (C2H5NH3)2CuCl4 crystallizes in a layered perovskite structure consisting of nearly isolated layers of corner-sharing ZnCl6 octahedra, and the interlayer distance is approximately 10 A, where the layers are separated by two layers of ethylammonium cations (C2H5NH3)+
The (C2H5NH3)2ZnCl4 undergoes phase transitions at 438 K, 376 K, and 320 K, which are denoted as the TC1, TC2, and TC3 with decreasing temperature

Summary

Introduction

Hybrid organic–inorganic compounds allow for the possibility of combining the properties of organic and inorganic materials at the molecular level.[1,2,3,4] This class of hybrid materials is very broad and offers a wide set of different structures, properties, and potential applications.[5,6,7,8,9,10,11,12] A new type of layered perovskite multiferroic, (C2H5NH3)2CuCl4, as a metal organic compound was found by Kundys et al.[6]. A study of the electrical, dielectric, and optical properties of (C2H5NH3)2ZnCl4 was reported by Mohamed et al.[15] They found that (C2H5NH3)2ZnCl4 is a layered perovskitetype compound that undergoes ve phase transitions at 231 K, 234 K, 237 K, 247 K, and 312 K as determined by differential scanning calorimetry (DSC).[15] The intensities of the endotherm peaks at 231 K, 237 K, and 312 K are very weak and perhaps correspond to second-order transformations. This compound is characterized by two 38032 | RSC Adv., 2019, 9, 38032–38037

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