Speaker
Description
We have extended our previous investigations on self- and collective dynamics of liquid water [1,2] to the case of tetrahydrofuran (THF). Neutron polarization analysis on a wide-angle time-of-flight spectrometer (PLET @ ISIS) has allowed measuring separately coherent and incoherent dynamic structure factor of deuterated THF with sub-meV resolution in a wide scattering vector (Q) range. The combination with Neutron Spin Echo (WASP @ ILL) experiments on deuterated and protonated THF with higher resolution has allowed to fully characterize the contributions to self- and collective dynamic structure factors also at low temperature. Interestingly, a low-Q mode (independent of Q), as that discerned in the collective dynamics of water and attributed to the reorganization of the HB-network, is also found in THF. The activation energy is however much lower, suggesting van der Waals interactions at the nature of the underlying process in this low-Q mode for the case of THF.
References
[1] A. Arbe, P. Malo de Molina, F. Alvarez, B. Frick, and J. Colmenero, Physical Review Letters 117, 185501 (2016).
[2] A. Arbe, G. Nilsen, J. R. Stewart, F. Alvarez, V. García-Sakai and J. Colmenero, Physical Review Research 2, 022015 (2020).
