460 / 2019-03-12 10:47:11

Controlled formation of amorphous ice on time scale from hour to millisecond

amorphous ice,Time-resolved x-ray diffraction,rapid (de)compression,metastable phase

全体主题 > High Pressure Physics and Materials Science

In this work, we present the formation of metastable phase in H2O at low temperatures using techniques of in-situ time-resolved x-ray diffraction and rapid (de)compression. The experimental results show the time scale in formation of metastable ice varies from hour to millisecond, depending on the temperature. We have a discussion on the factors, which affects transition pathways, and the mechanism of formation of metastable phase. It is found that the formation of metastable ice are results of competition between external (de)compression rate, energy barrier and temperature. The crossover temperature, above and below which the phase transition pathways are different, is shown to have an exponential relationship with the threshold compression rate. The present results provide important insight into the dynamic property of the phase transitions in addition to the static study.