Phase transitions in solid Kr–CH₄ solutions and rotational excitations in phase II
The heat capacity CP of solid Kr–n CH₄ solutions with the CH₄ concentrations n = 0.82, 0.86, 0.90 as well as solutions with n = 0.90, 0.95 doped with 0.002 O₂ impurity has been investigated under equilibrium vapor pressure over the interval 1–24 K. The (T,n)-phase diagram was refined and the regio...
Збережено в:
| Дата: | 2007 |
|---|---|
| Автори: | , , |
| Формат: | Стаття |
| Мова: | English |
| Опубліковано: |
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
2007
|
| Назва видання: | Физика низких температур |
| Теми: | |
| Онлайн доступ: | http://dspace.nbuv.gov.ua/handle/123456789/121774 |
| Теги: |
Додати тег
Немає тегів, Будьте першим, хто поставить тег для цього запису!
|
| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Phase transitions in solid Kr–CH₄ solutions and rotational excitations in phase II / M.I. Bagatskii, D.A. Mashchenko, V.V. Dudkin // Физика низких температур. — 2007. — Т. 33, № 6-7. — С. 728-734. — Бібліогр.: 34 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| Резюме: | The heat capacity CP of solid Kr–n CH₄ solutions with the CH₄ concentrations n = 0.82, 0.86, 0.90 as
well as solutions with n = 0.90, 0.95 doped with 0.002 O₂ impurity has been investigated under equilibrium
vapor pressure over the interval 1–24 K. The (T,n)-phase diagram was refined and the region of two-phase
states was determined for Kr–n CH₄ solid solutions. The contribution of the rotational subsystem, Crot, to
the heat capacity of the solutions has been separated. Analysis of Crot(T) at T < 3 K made it possible to estimate
the effective conversion times τ and the energy gaps E₁ and E₂ between the tunnel levels of the A-, T- and A-, E-nuclear-spin species of CH₄ molecules in the orientationally ordered subsystem, and to determine
the effective energy gaps E₁ between the lowest levels of the A- and T- species. The relations τ(n) and E₁(n)
stem from changes of the effective potential field caused as the replacement of CH₄ molecules by Kr atoms
at sites of the ordered sublattices. The effective gaps EL between a group of tunnel levels of the ground-state
libration state and the nearest group of excited levels of the libration state of the ordered CH₄ molecules in
the solutions with n = 0.90 (EL = 52 K) and 0.95 (EL = 55 K) has been estimated. |
|---|