Crystal structure,phase transitions and dielectric properties of the mixed compound [Cs0.92(NH4)0.08]2HgBr4 |
| |
| Institution: | 1. Universitat Internacional de Catalunya, Barcelona, Catalonia, Spain;2. Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine, Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain;1. Department of Research, Canadian Memorial Chiropractic College, Toronto, ON, Canada;2. Parker Research Center, Parker University, Dallas, Texas;3. McMaster University, Toronto, ON, Canada;4. Embody Physiotherapy & Wellness (Private Practice), Andrews University, Sewickley, Pennsylvania;5. Undergraduate Department, Canadian Memorial Chiropractic College, Toronto, ON, Canada;6. Physical Medicine and Rehabilitation, UT Southwestern Medical Center, Dallas Texas;7. Department of Family Medicine, University of Calgary, Calgary, AB, Canada;8. Canadian Memorial Chiropractic College, Calgary, AB, Canada;9. Texas Chiropractic College, Pasadena, Texas;1. Department of Psychiatry and Psychotherapy, LVR-Klinikum Düsseldorf, Germany; Medical Faculty, Heinrich Heine University Düsseldorf, Germany;2. Medical Psychology | Neuropsychology and Gender Studies & Center for Neuropsychological Diagnostics and Intervention (CeNDI), Faculty of Medicine and University Hospital Cologne, University of Cologne, Germany;1. Institut Pasteur, Unité Biologie Evolutive de la Cellule Microbienne, 02-Bâtiment Duclaux, 28 rue du Dr Roux, 75015 Paris, France;2. Environmental Science Program, Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, 2713 Doha, Qatar;1. Sultan Moulay Slimane University of Beni Mellal, MRI Lab, FP Khouribga, BP. 145, 2500 Khouribga, Morocco;2. Moulay Ismail University of Meknes, Laboratory of Physical Chemistry, Materials and Environment, Faculty of Science and Technology, Errachidia, Morocco;3. Laboratory of Process and Environmental Engineering, Higher School of Technology, Hassan II University of Casablanca, Morocco;4. Sultan Moulay Slimane University of Beni Mellal, Laboratoire LITA, FST, Beni Mellal, Morocco |
| |
| Abstract: | The crystal structure of Cs0.92 (NH4)0.08]2HgBr4 was determined by three-dimensional X-ray diffraction analysis. The space group is Pnma with a = 10.210(2), b = 7.928(1), c = 13.883(1)Å and Z = 4 at 293K. The structure was refined to R = 0.067. The distribution of atoms can be described as isolated HgBr42−tetrahedra , Cs+ and NH4+ cations. The main feature of this structure is the coexistence of two types of bonds: Cs+ Br− ionic bonds and NH…Br hydrogen bonds ensuring the cohesion of the crystal. Dicaesium-ammonium tetrabromomercurate exhibits three phase transitions at T1 = 237K, T2 = 244K and T3 = 513K. These transitions were detected by differential scanning calorimetry and analysed by dielectric measurements using the impedance and modulus spectroscopy techniques. The phase change at high temperature is related with the orientational disorder of NH4+ cations. Transport properties in this material appear to be due to a H+ ion hopping mechanism. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
