Unusual Grüneisen and Bridgman parameters of low-density amorphous ice and their implications on pressure induced amorphization
2005 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 122, no 12, 124710- p.Article in journal (Refereed) Published
The low-temperature limiting value of the Grüneisen parameter for low-frequency phonons and the density dependence of the thermal conductivity (Bridgman parameter) of low-density amorphous (LDA) ice, high-density amorphous (HDA) ice, hexagonal ice Ih, and cubic ice Ic were calculated from high-pressure sound velocity and thermal conductivity measurements, yielding negative values for all states except HDA ice. LDA ice is the first amorphous state to exhibit a negative Bridgman parameter, and negative Grüneisen parameters are relatively unusual. Since Ih, Ic, and LDA ice all transform to HDA upon pressurization at low temperatures and share the unusual feature of negative Grüneisen parameters, this seems to be a prerequisite for pressure induced amorphization. We estimate that the Grüneisen parameter increases at the ice Ih to XI transition, and may become positive in ice XI, which indicates that proton-ordered ice XI does not amorphize like ice Ih on pressurization.
Place, publisher, year, edition, pages
2005. Vol. 122, no 12, 124710- p.
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:umu:diva-12309DOI: 10.1063/1.1869352OAI: oai:DiVA.org:umu-12309DiVA: diva2:151980