The mechanism of phase transitions in azide perovskites probed by vibrational spectroscopy
- Resource Type
- Authors
- Monika Trzebiatowska; Maciej Ptak
- Source
- Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 214:184-191
- Subject
- Tetramethylammonium
Phase transition
Hydrogen bond
Infrared spectroscopy
02 engineering and technology
Crystal structure
010402 general chemistry
021001 nanoscience & nanotechnology
01 natural sciences
Atomic and Molecular Physics, and Optics
0104 chemical sciences
Analytical Chemistry
Crystallography
symbols.namesake
chemistry.chemical_compound
chemistry
symbols
Azide
0210 nano-technology
Raman spectroscopy
Instrumentation
Spectroscopy
Perovskite (structure)
- Language
- ISSN
- 1386-1425
The temperature-dependent IR and Raman spectroscopy has been used to study the phase transitions in manganese-azide frameworks with either dimethylammonium (DMA+) or tetramethylammonium (TMA+) cations which adopt a perovskite-like crystal structure. The phase transition in DMA-analogue seems to be associated with cooperative tilting of MnN6 octahedra and order-disorder of hydrogen bonds while in TMA-analogue it is more complex and composed of several processes, including the motions of both manganese-azide framework and tetramethylammonium cations and their possible coupling. Our results are in agreement with the data received from crystallographic and dielectric measurements in the case of TMA-analogue and we have demonstrated the importance of order-disorder of hydrogen bonds in the case of DMA-analogue which previously has not been taken into account.