TY - GEN
T1 - Phonon Kinetics at the Solid to Liquid Phase Transition
AU - Davie, Alex
AU - Vandrevala, Farah
AU - Deng, Yanting
AU - George, Deepu
AU - Sylvester, Eric
AU - Korter, Timothy
AU - Einarsson, Erik
AU - Benedict, Jason
AU - Markelz, Andrea
N1 - Funding Information:
The results support that multiple H-bonds must collectively break for the phase change to occur. III. ACKNOWLEDGEMENTS This work supported by NSF grants DBI 1556359 and MCB 1616529, and Los Alamos National Laboratory.
Publisher Copyright:
© 2020 IEEE.
PY - 2020/11/8
Y1 - 2020/11/8
N2 - Terahertz time domain spectroscopy is used to measure the melting kinetics of fructose molecular crystals. Combining single crystal anisotropy measurements with density functional calculations we assign the phonon frequencies and interrogate how specific phonons behave with melting. While nearly all the low frequency phonons continuously red shift with heating and melting, the lowest energy phonon polarized along the c-axis blue shifts at the melting temperature, suggesting an initial structural change immediately before melting. We find that the kinetics follow a 3D growth model with large activation energies consistent with previous DSC measurements. The large activation energies indicate multiple H-bonds must break collectively for the transition. The results suggest THz TDS with sub picosecond resolution could be used to measure ultra-fast kinetics.
AB - Terahertz time domain spectroscopy is used to measure the melting kinetics of fructose molecular crystals. Combining single crystal anisotropy measurements with density functional calculations we assign the phonon frequencies and interrogate how specific phonons behave with melting. While nearly all the low frequency phonons continuously red shift with heating and melting, the lowest energy phonon polarized along the c-axis blue shifts at the melting temperature, suggesting an initial structural change immediately before melting. We find that the kinetics follow a 3D growth model with large activation energies consistent with previous DSC measurements. The large activation energies indicate multiple H-bonds must break collectively for the transition. The results suggest THz TDS with sub picosecond resolution could be used to measure ultra-fast kinetics.
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U2 - 10.1109/IRMMW-THz46771.2020.9370643
DO - 10.1109/IRMMW-THz46771.2020.9370643
M3 - Conference contribution
AN - SCOPUS:85103150801
T3 - International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz
SP - 54
BT - 2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz 2020
PB - IEEE Computer Society
T2 - 45th International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz 2020
Y2 - 8 November 2020 through 13 November 2020
ER -