scholarly journals Orientational Ordering in Solid Hydrogen: Dependence of Critical Temperature and Concentration on Density

1979 ◽  
Vol 43 (5) ◽  
pp. 377-380 ◽  
Author(s):  
Isaac F. Silvera ◽  
R. Jochemsen
Keyword(s):  
Critical Temperature ◽  
Solid Hydrogen ◽  
Orientational Ordering

Orientational ordering in solid hydrogen

1976 ◽  
Vol 37 (7-8) ◽  
pp. 981-989 ◽  
Author(s):  
N.S. Sullivan
Keyword(s):  
Solid Hydrogen ◽  
Orientational Ordering

Orientational Ordering in Solid Hydrogen

1967 ◽  
Vol 158 (2) ◽  
pp. 530-536 ◽  
Author(s):  
G. M. Bell ◽  
W. M. Fairbairn
Keyword(s):  
Solid Hydrogen ◽  
Orientational Ordering

The Fundamental Infrared Absorption Band of Ortho-Enriched Solid Hydrogen

1972 ◽  
Vol 50 (18) ◽  
pp. 2063-2073 ◽  
Author(s):  
S. A. Boggs ◽  
M. J. Clouter ◽  
H. L. Welsh
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Rotational Transition ◽  
Solid Hydrogen ◽  
Low Energy ◽  
Side Band ◽  
Disorder Phase Transition ◽  
Orientational Ordering ◽  
Ordered State ◽  
Orientational Transitions

Spectra of the infrared fundamental band of solid hydrogen with orthohydrogen concentrations in the range 75 to ~99% were recorded at 1.05 and ~5 K, i.e. below and above the order–disorder phase transition which occurs at 2.8 K for pure o-H2. The effect of "impurity" para molecules in the o-H2 lattice could thus be studied with and without orientational ordering of the o-H2 molecules. The zero-phonon Q1, S1(0), and S1(1) features are of particular interest, and are interpreted in terms of travelling vibrational, rotational, and orientational excitations (vibrons, rotons, and librons). The Q branch for ~100% o-H2 in the ordered state shows a structured side band, shifted by ~6–26 cm−1 from the Q1(1) frequency and due to one- and two-libron excitations; in the disordered state this becomes a Boltzmann-modified band of half-width 12 cm−1, centered at the Q1(1) frequency, and due to predominantly low-energy orientational transitions of interacting o-H2 molecules. The S1(0) group of maxima in the ordered state is interpreted as the superposition of the transitions, Q1(1) + S0(0) and Q1(1) + S0(0) + libron, where Q1(1) is an o-H2 vibron and S0(0) is the localized rotational transition of an impurity p-H2 molecule, the J = 2 level of which is split into three sublevels by the C3i field of the Pa3 crystal structure.

scholarly journals Quantum and Classical Orientational Ordering in Solid Hydrogen

1997 ◽  
Vol 78 (6) ◽  
pp. 1066-1069 ◽  
Author(s):  
I. I. Mazin ◽  
Russell J. Hemley ◽  
A. F. Goncharov ◽  
Michael Hanfland ◽  
Ho-kwang Mao
Keyword(s):  
Solid Hydrogen ◽  
Orientational Ordering

Evidence from x-ray diffraction of orientational ordering in phase III of solid hydrogen at pressures up to 183 GPa

2010 ◽  
Vol 82 (6) ◽  
Author(s):  
Yuichi Akahama ◽  
Manabu Nishimura ◽  
Haruki Kawamura ◽  
Naohisa Hirao ◽  
Yasuo Ohishi ◽  
...  
Keyword(s):  
Solid Hydrogen ◽  
Phase Iii ◽  
X Ray Diffraction ◽  
X Ray ◽  
Orientational Ordering

scholarly journals Effect of Orientational Ordering in Solid Hydrogen at Low Ortho Concentration

1979 ◽  
Vol 61 (2) ◽  
pp. 692-694
Author(s):  
M. Yamashita ◽  
H. Nakano ◽  
S. Homma
Keyword(s):  
Solid Hydrogen ◽  
Orientational Ordering

Orientational ordering in solid hydrogen

1987 ◽  
Vol 65 (11) ◽  
pp. 1463-1470 ◽  
Author(s):  
N. S. Sullivan ◽  
C. M. Edwards ◽  
Y. Lin ◽  
D. Zhou
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Solid Hydrogen ◽  
Order Parameters ◽  
Para Hydrogen ◽  
Hydrogen Mixtures ◽  
Orientational Ordering ◽  
Nuclear Magnetic

The orientational ordering in solid ortho–para hydrogen mixtures is reviewed with emphasis on dilute mixtures for which a glass-like freezing of the randomly distributed quantum rotators is observed. The interpretation of the various nuclear magnetic resonance experiments used to monitor the relevant order parameters is discussed, and a summary is given of the current consensus and outstanding problems concerning the nature of the ordering in random dilute mixtures.

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