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Raman spectroscopy study on terephthalamide crystal at high pressures
JiaRui Liu1, DongFei Li2, NaiCui Zhai3
1Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Normal University, Changchun 130103, Jilin Province, People's Republic of China.
Summary
This study reveals two pressure-induced phase transitions in terephthalamide (TPA) crystals at 1.3 GPa and 5.2 GPa using Raman spectroscopy. These findings enhance understanding of TPA
Area of Science:
- Materials Science
- Solid-State Chemistry
- Spectroscopy
Background:
- Terephthalamide (TPA) is a significant organic compound with potential applications.
- Understanding its structural behavior under pressure is crucial for materials science.
- Previous studies may not have fully elucidated its high-pressure phase transitions.
Purpose of the Study:
- To investigate the structural stability of terephthalamide (TPA) crystals under high pressure.
- To identify and characterize pressure-induced phase transitions in TPA.
- To provide a detailed analysis of TPA's structural response to applied pressure.
Main Methods:
- High-pressure experiments utilizing a diamond anvil cell (DAC) at room temperature.
- In-situ Raman spectroscopy to monitor structural changes.
- Density Functional Theory (DFT) calculations for vibrational mode assignment at ambient conditions.
Main Results:
- Two distinct pressure-induced phase transitions were observed in TPA at approximately 1.3 GPa and 5.2 GPa.
- Phase I transitions to Phase II at ~1.3 GPa, and Phase II transitions to Phase III at ~5.2 GPa.
- Significant changes in Raman spectra, including new peak appearances and disappearances, confirmed these transitions.
Conclusions:
- Terephthalamide (TPA) undergoes two distinct structural phase transitions under compression.
- Raman spectroscopy is an effective tool for identifying pressure-induced phase transitions in crystalline materials.
- The identified phase transitions provide critical data for the fundamental understanding of TPA's solid-state behavior.
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