Related Experiment Video
Updated: Jan 29, 2026

Measurement of Bioelectric Current with a Vibrating Probe
Published on: January 4, 2011
The mechanism of phase transitions in azide perovskites probed by vibrational spectroscopy
1Institute of Low Temperature and Structure Research PAS, Okólna Str. 2, 50-422 Wrocław, Poland.
Abstract:
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.
Related Concept Videos
Phase Transitions
Phase Transitions: Melting and Freezing
Phase Transitions: Sublimation and Deposition
Phase Transitions: Vaporization and Condensation
IR Spectroscopy: Molecular Vibration Overview
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
IR Spectroscopy: Hooke's Law Approximation of Molecular Vibration
According to Hooke's law, the vibrational frequency is directly proportional to...

