Pressure induced phase transformations in diisopropylammonium bromide
| Autor: | Shradhanjali Sahoo, Sharat Chandra, Pattukkannu Murugavel, Ch. Thirmal, K. K. Pandey, T. R. Ravindran, Velaga Srihari |
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| Rok vydání: | 2019 |
| Předmět: |
Diffraction
Materials science 02 engineering and technology Triclinic crystal system 010402 general chemistry 01 natural sciences Inorganic Chemistry symbols.namesake chemistry.chemical_compound Bromide Materials Chemistry Physical and Theoretical Chemistry Hydrogen bond 021001 nanoscience & nanotechnology Condensed Matter Physics Ferroelectricity 0104 chemical sciences Electronic Optical and Magnetic Materials Crystallography chemistry X-ray crystallography Ceramics and Composites symbols 0210 nano-technology Raman spectroscopy Monoclinic crystal system |
| Zdroj: | Journal of Solid State Chemistry. 274:182-187 |
| ISSN: | 0022-4596 |
| DOI: | 10.1016/j.jssc.2019.03.025 |
| Popis: | Effect of high pressure on ferroelectric diisopropylammonium bromide (DIPAB) is investigated using Raman spectroscopy and angle-dispersive x-ray diffraction (XRD) measurements using a diamond anvil cell up to ∼10 GPa. Raman spectroscopic studies indicate that the monoclinic (m-II) ferroelectric phase of DIPAB is unstable under slight compression, leading to changes in molecular conformation. We have observed new peaks appearing in the lattice mode region and CH3 stretching region giving indication of conformational change. XRD investigations reveal that the m-II phase (space group P21) is partially transformed into a centrosymmetric, non-polar triclinic (P-1) structure at 0.7 GPa. Ferroelectricity is expected to weaken under compression above 0.7 GPa and ferroelectricity may disappear at a very high pressure when the m-II phase fully converted into triclinic P-1 phase. On releasing the pressure the ambient structure is fully recovered. The role of hydrogen bonds in the phase transformation is also discussed. |
| Databáze: | OpenAIRE |
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