Structural transitions in ice samples at low temperatures and pressures |
| |
Authors: | V B Efimov A N Izotov A A Levchenko L P Mezhov-Deglin S S Khasanov |
| |
Institution: | 1.Institute of Solid State Physics,Russian Academy of Sciences,Chernogolovka, Moscow region,Russia |
| |
Abstract: | The structure of ice samples formed in the decay of a water impurity gel at temperatures above 4 K and atmospheric pressure
has been examined. The X-ray diffraction analysis indicates that three phases coexist in the initial sample at temperatures
of 85–110 K. These phases are amorphous ice occupying up to 30% of the sample volume, cubic-phase ice I
c metastable at low pressures (∼60%), and normal hexagonal ice I
h (≤6%). The characteristic sizes of crystals of the cubic and hexagonal phases are about 6 and 30 nm, respectively. The amorphous
phase at annealing above 110 K is gradually transformed to the crystalline phase both cubic and hexagonal. This transition
is accompanied by two processes, including a fast increase in the sizes of cubicphase nanocrystals and the partial transition
of the cubic phase I
c to the hexagonal one I
h. Hexagonal ice I
h prevails in the bulk of the sample above 200 K. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|