The high temperature phase transition in solid mixtures of CH 4 and CD 4 at elevated pressure
Abstract
I-II phase transitions in solid (1- x)CH 4- xCD 4 mixtures have been investigated up to a pressure of 2 kbar by means of proton spin-lattice relaxation measurements. It is shown that the linear behaviour of the transition temperature as a function of the composition also occurs at elevated pressures, except for x between about 0.05 and 0.15. In this concentration interval, the transitions occur at temperatures lower than can be expected from a shift of the transition temperature proportional to x. It is shown that the linear x-dependence of the I-II transition temperature at zero pressure can be derived from a mean field treatment based on the James and Keenan model for orientational phase transitions.
- Publication:
-
Physica B Condensed Matter
- Pub Date:
- September 1989
- DOI:
- 10.1016/0921-4526(89)90004-5
- Bibcode:
- 1989PhyB..159..249L