Temperature-dependent kinetic pathways featuring distinctive thermal-activation mechanisms in structural evolution of ice VII

Lin, Chuanlong; Liu, Xuqiang; Yong, Xue; Tse, John S.; S. Smith, Jesse; J. English, Niall; Wang, Bihan; Li, Mei; Yang, Wenge; Mao, Ho-Kwang

doi:10.1073/pnas.2007959117

DOE OSTI · 1634239

Temperature-dependent kinetic pathways featuring distinctive thermal-activation mechanisms in structural evolution of ice VII

Lin, Chuanlong·Liu, Xuqiang·Yong, Xue·Tse, John S.·S. Smith, Jesse·J. English, Niall·Wang, Bihan·Li, Mei·Yang, Wenge·Mao, Ho-Kwang

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Abstract

Significance The kinetics of the structural evolution from crystalline ice (ice VII or ice VIII) toward thermodynamically stable ice I at ambient pressure have been characterized using time-resolved in situ X-ray diffraction. The time resolution captures events that were not observed previously and reveals a complex kinetic pathway with three distinctive transitions, i.e., amorphization, amorphous–amorphous, and crystallization of amorphous ice into ice I. The first two transitions exhibit different thermally activated mechanism above and below 110 K. Molecular-dynamics simulations show the transition involves a large change in density and substantial displacements of water at the nanoscale. This study presents a perspective on the metastability and complexity of the energy landscape in temperature/time-dependent structural evolution in amorphous ices.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY amorphization high-density amorphous ice ice low-density amorphous ice

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Lin, Chuanlong, Liu, Xuqiang, Yong, Xue, Tse, John S., S. Smith, Jesse, J. English, Niall, Wang, Bihan, Li, Mei, Yang, Wenge, Mao, Ho-Kwang. 2020-06-22. Temperature-dependent kinetic pathways featuring distinctive thermal-activation mechanisms in structural evolution of ice VII. https://doi.org/10.1073/pnas.2007959117

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