Orientational ordering in solid D/sub 2/ from NMR studies. II. The cubic ordered phase
An NMR study in the cubic phase of D/sub 2/ which exhibits long-range orientational order is reported. The spin systems in both para D/sub 2/ (with angular momentum J = 1 and spin I = 1) and in ortho D/sub 2/ (with J = 0 and I = 2) were investigated. The integrated intensity ratio of the I = 1 and I = 2 components in the solid echo, the NMR line shapes obtained by Fourier transforming the solid echoes, and the longitudinal relaxation times for the I = 1 and I = 2 systems are presented. Samples with D/sub 2/ concentration X between 0.69 and 0.62 were studied over the temperature range 0.12 < T < 4K. Measurements were carried out before and after repeated thermal cycling through the ordering transition to study the effect of this cycling on the temperature dependence of the relaxation times. The complex behavior of these relaxation times was found to be similar to that in cubic H/sub 2/ at a comparable concentration, and the interpretation of this behavior is discussed. Over most of the temperature range, the relaxation time of the I = 2 spins is larger than that of the I = 1 spins and is believed to be determined by cross-relaxation with the latter, whose intrinsic spin-lattice relaxation is observed. However, at low enough temperature, the relaxation time for the I = 2 spins is found to be shorter than that for the I = 1 spins, and this observation cannot be understood on the basis of predictions. Furthermore, the I = 2 relaxation time in this temperature region is found to depend on the position within the NMR line. Another observation not yet understood is that the ratio of the integrated intensities S(I = 1)/S(I = 2) in the solid echo is smaller than the theoretically predicted one by about 20%. The NMR line shapes for the I = 1 spins in the ordered phase obtained from pulse measurements are compared with those from continuous-wave methods and to those from H/sub 2/.
- Research Organization:
- Boeing Aerospace Co., Seattle, WA
- OSTI ID:
- 6992300
- Journal Information:
- J. Low Temp. Phys.; (United States), Vol. 65:1/2
- Country of Publication:
- United States
- Language:
- English
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SUPERCONDUCTIVITY AND SUPERFLUIDITY
DEUTERIUM
CUBIC LATTICES
NMR SPECTRA
ORDER PARAMETERS
FOURIER TRANSFORMATION
HYDROGEN
LINE WIDTHS
NUCLEAR MAGNETIC RESONANCE
QUANTUM CRYSTALS
RELAXATION TIME
SPIN ECHO
SPIN ORIENTATION
SPIN-LATTICE RELAXATION
TEMPERATURE DEPENDENCE
THERMAL CYCLING
ULTRALOW TEMPERATURE
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALS
ELEMENTS
HYDROGEN ISOTOPES
INTEGRAL TRANSFORMATIONS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
NONMETALS
NUCLEI
ODD-ODD NUCLEI
ORIENTATION
RELAXATION
RESONANCE
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STABLE ISOTOPES
TRANSFORMATIONS
656002* - Condensed Matter Physics- General Techniques in Condensed Matter- (1987-)