title: Evidence for liquid water during the high-density to low-density amorphous ice transition.
abstract: Polymorphism of water has been extensively studied, but controversy still exists over the phase transition between high-density amorphous (HDA) and low-density amorphous (LDA) ice. We report the phase behavior of HDA ice inside high-pressure cryocooled protein crystals. Using X-ray diffraction, we demonstrate that the intermediate states in the temperature range from 80 to 170 K can be reconstructed as a linear combination of HDA and LDA ice, suggesting a first-order transition. We found evidence for a liquid state of water during the ice transition based on the protein crystallographic data. These observations open the possibility that the HDA ice induced by high-pressure cryocooling is a genuine glassy form of high-density liquid.
authors.affiliation: Cornell High Energy Synchrotron Source, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Chae Un
authors.initials: CU
authors.lastname: Kim
authors.forename: Buz
authors.initials: B
authors.lastname: Barstow
authors.forename: Mark W
authors.initials: MW
authors.lastname: Tate
authors.forename: Sol M
authors.initials: SM
authors.lastname: Gruner