Ice XV is a crystalline form of
ice
Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaq ...
, the proton-ordered form of
ice VI
Ice VI is a form of ice that exists at high pressure at the order of about 1 GPa (= 10 000 bar) and temperatures ranging from 130 up to 355 Kelvin (−143 °C up to 82 °C); see also the phase diagram of water. Its discovery and ...
. It is created by cooling hydrochloric-acid-doped water to around 130
K at 1
GPa
Grading in education is the process of applying standardized measurements for varying levels of achievements in a course. Grades can be assigned as letters (usually A through F), as a range (for example, 1 to 6), as a percentage, or as a numbe ...
(9820
atm).
Ordinary water ice is known as
ice Ih, (in the
Bridgman nomenclature). Different types of ice, from
ice II
Ice II is a rhombohedral crystalline form of ice with a highly ordered structure. It is formed from ice Ih by compressing it at a temperature of 198 K at 300 MPa or by decompressing ice V. When heated it undergoes transformation to ice III. Ordi ...
to ice XVI, have been created in the laboratory at different temperatures and pressures.
On 14 June 2009, Christoph Salzmann at the University of Oxford and colleagues reported having created ice XV and say that its properties differ significantly from those predicted. In particular, ice XV is
antiferroelectric Antiferroelectricity is a physical property of certain materials. It is closely related to ferroelectricity; the relation between antiferroelectricity and ferroelectricity is analogous to the relation between antiferromagnetism and ferromagnetism.
...
rather than
ferroelectric
Ferroelectricity is a characteristic of certain materials that have a spontaneous electric polarization that can be reversed by the application of an external electric field. All ferroelectrics are also piezoelectric and pyroelectric, with the add ...
as had been predicted.
References
*
Water ice
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