Phase Transition in the Compound NH3(CH2)5NH3TlCl5 |
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Authors: | M Abdi F Zouari S Chaabouni Z Elaoud A Ben Salah |
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Institution: | 1. Faculté des Sciences de Sfax , Laboratoire des Sciences de Matériaux et d'Environnement , 3018, Tunisia;2. Laboratoire de Chimie du solide , ENIS , Sfax, 3038, Tunisia |
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Abstract: | Penthylene diammonium pentachlorothallate(III) exhibits a phase transition at 316 K <artwork name="GPHT21157eu1"> This transition has been characterized by optical birefringence, dielectric measurements differential scanning calorimetry and spectroscopic measurements on polycrystalline samples. The space group and the cell parameters of phase I were determined by X-ray diffraction from single crystals. Phase I has space group P212121, with Z = 4, a = 7.696(3), b = 13.2890(17) and c = 13.503(18) Å. The transition is both displacive and order-disorder involving mainly conformational changes of the organic chain NH3(CH2)5NH3]2+ coupled with distortion of the TlCl6 octahedra. This behaviour and the crystal dynamics will be discussed and compared with those found in the literature for homologous compounds. |
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Keywords: | Dielectric Birefringence Order-disorder Transition |
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