Journal article
Quasi-Elastic Neutron Scattering in Normal and Deuterated p-azoxyanisole
The neutron scattering from normal (protonated p-PAA) and deuterated (d-PAA) para-azoxyanisole has been measured in the isotropic liquid phase at momentum transfers 0.8 A-1 < Q < 5 A-1 and energy transfers (ℏ)ω up to 25 mev. For p-PAA the spectra can be interpreted on a model of continuous, uniaxial rotational diffusion around the long molecular axis with diffusion coefficient D = 0.18 meV.
For d-PAA, which is a coherent scatterer, the structure of the liquid manifests itself through the structure factor S(Q), which modulates the scattered intensity and introduces an energy narrowing (de Gennes narrowing) at the maxima of S(Q). Data on unoriented samples of d-PAA in the nematic phase are indistinguishable from those measured in the isotropic phase, suggesting that no collective excitations of the nematic phase do exist.
Language: | English |
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Year: | 1978 |
Pages: | 157-160 |
ISSN: | 00318949 , 14024896 and 02811847 |
Types: | Journal article |
DOI: | 10.1088/0031-8949/18/2/013 |