Phase-resolved sum-frequency generation measurements combined with molecular dynamics simu- lations are employed to study the effect of temperature on the molecular arrangement of water on the basal face of ice. The topmost monolayer, interrogated through its nonhydrogen-bonded, free O-H stretch peak, exhibits a maximum in surface H-bond density around 200 K. This maximum results from two competing effects: above 200 K, thermal fluctuations cause the breaking of H bonds; below 200 K, the formation of bulklike crystalline interfacial structures leads to H-bond breaking. Knowledge of the surface structure of ice is critical for understanding reactions occurring on ice surfaces and ice nucleation.

NWO
APS
doi.org/10.1103/PhysRevLett.119.133003
Phys. Rev. Lett.
Ultrafast Spectroscopy

Smit, W., Tang, F., Sanchez, A., Backus, E., Xu, L., Hasegawa, T., … Nagata, Y. (2017). Excess Hydrogen Bond at the Ice-Vapor Interface around 200 K. Phys.Rev.Lett., 119(Article number: 133003), 1–5. doi:10.1103/PhysRevLett.119.133003