Low Temperature Physics: 29, 378 (2003); https://doi.org/10.1063/1.1542500 (4 pages)
Fizika Nizkikh Temperatur: Volume 29, Number 5 (May 2003), p. 508-513    ( to contents , go back )

Orientation ordering in J = 1 solid hydrogens at crystal fields

T.N. Antsygina, S.M. Tretjak, Yu.A. Freiman

B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Science of Ukraine, 47 Lenin Ave., Kharkov, 61103, Ukraine
E-mail: freiman@ilt.kharkov.ua

R.J. Hemley

Geophysical Laboratory and Center for High Pressure Research Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington
pos Анотація:

Received March 7, 2002


A system of quantum linear rotators with a rotational quantum number J = 1 is considered at a crystal field. An equation for orientation order parameter is derived, and the critical parameters, the phase separation curve and the lines of overheating and overcooling points are obtained. It is shown that in terms of the thermodynamics the behavior of the above linear rotators in the classical case and in the extremely quantum (J = 1) one is identical. For positive values of the crystal field there also exist parallels between orientation phase transitions in a system of rotators with J = 1 and phase transitions in a liquid-vapor system. It is shown that the consideration of J > 1 states results in a radical change of the phase transition behavior in a system of rotators: instead of the sole critical point typical for the J = 1 system, there appears a line of critical points.

64.70.-p - Specific phase transitions

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