NCAFM2023 Programme Booklet

Jonggeun Hwang 1 , Dongha Shin 1,2 , Manhee Lee 3,4 , Brendan T. Deveney 4 , Xingcai Zhang 4,5* & Wonho Jhe 1* EXPERIMENTAL OBSERVATION OF ICE NUCLEATION UNDER ATOMIC SCALE CONFINEMENT AT ROOM TEMPERATURE

1 Center for 0D Nanofluidics, Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea 2 Department of Chemistry and Chemical Engineering, Inha University, Incheon 22212, Korea 3 Department of Physics, Chungbuk National University, Cheongju, Chungbuk 28644, Korea 4 John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA 5 School of Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA

*Corresponding author. E-mail: whjhe@snu.ac.kr, xingcai@mit.edu

Extensive studies to understand the heterogeneous nucleation have been performed, but only limited to a given specific configuration. Despite many computational studies, experimental probing of heterogeneous nucleation process in nano-confinement still remains unsolved due to it being very challenging. Here, we investigate the confinement-induced ice nucleation of a single water nano-meniscus between Ag coated tip and mica using tip-enhanced Raman spectroscopy (TERS). A new DDAA peak emerges in the OH stretching band as the confinement is stronger. We assign the new DDAA peak as the ice-vii-like structure signal based on the spectroscopic uniqueness of the ice-vii well-known high-pressure ice phase at room temperature. We also observe the exchange between two ice phase peaks, the ice-vii-like peak and the ice-ih peak, as the confinement is weakened. We believe that the confinement effect may be affected to nucleate the ice-vii-like structure by lowering the pressure threshold. Our result is the experimental demonstration of a new pathway to the ice-ih by confinement-induced heterogeneous nucleation through the ice-vii. And this result will provide the fundamental understanding of heterogeneous nucleation.

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