High frequency dynamics of liquid methanol and toluene. Contribution of molecular rotational diffusion to inelastic neutron scattering

1972 ◽  
Vol 6 ◽  
pp. 135 ◽  
Author(s):  
B. K. Aldred ◽  
G. C. Stirling ◽  
J. W. White
Keyword(s):  
Neutron Scattering ◽  
High Frequency ◽  
Inelastic Neutron Scattering ◽  
Rotational Diffusion ◽  
Inelastic Neutron

scholarly journals Inelastic Neutron Scattering from Ice and Other Proton-containing Substances

1978 ◽  
Vol 21 (85) ◽  
pp. 231-240 ◽  
Author(s):  
Bruno Dorner
Keyword(s):  
Neutron Scattering ◽  
Phonon Dispersion ◽  
Inelastic Neutron Scattering ◽  
Rotational Diffusion ◽  
High Energy ◽  
Inelastic Neutron ◽  
High Energy Resolution ◽  
Very High Energy ◽  
Proton Disorder ◽  
The Difference

Abstract A brief introduction to neutron scattering is given with special emphasis on the difference between coherent and incoherent contributions. The following report of recent work on ice contains the determination and verification of some phonon dispersion curves, and outlines the state of the art on diffuse scattering due to the proton disorder. Results on “two-dimensional ice” in copper formate tetrahydrate are of great interest as this system exhibits a phase transformation below which the protons are ordered. The study of rotational diffusion and of the tunnel splitting of the rotational ground state of molecules which contain protons is discussed in some detail. These investigations are now possible with very high energy resolution ΔE ≈ 5 × 10-8 eV (4 • 10-4 cm- 1 or 12 MHz).

Inelastic Neutron Scattering from Ice and Other Proton-containing Substances

1978 ◽  
Vol 21 (85) ◽  
pp. 231-240
Author(s):  
Bruno Dorner
Keyword(s):  
Neutron Scattering ◽  
Phonon Dispersion ◽  
Inelastic Neutron Scattering ◽  
Rotational Diffusion ◽  
High Energy ◽  
Inelastic Neutron ◽  
High Energy Resolution ◽  
Very High Energy ◽  
Proton Disorder ◽  
The Difference

AbstractA brief introduction to neutron scattering is given with special emphasis on the difference between coherent and incoherent contributions. The following report of recent work on ice contains the determination and verification of some phonon dispersion curves, and outlines the state of the art on diffuse scattering due to the proton disorder. Results on “two-dimensional ice” in copper formate tetrahydrate are of great interest as this system exhibits a phase transformation below which the protons are ordered. The study of rotational diffusion and of the tunnel splitting of the rotational ground state of molecules which contain protons is discussed in some detail. These investigations are now possible with very high energy resolution ΔE ≈ 5 × 10-8 eV (4 • 10-4 cm- 1 or 12 MHz).

Neutron Scattering Studies of C61H2

1994 ◽  
Vol 359 ◽  
Author(s):  
D. A. Neumann ◽  
J. E. Fischer ◽  
J. R. D. Copley ◽  
P. A. Heiney ◽  
J. J. Rush ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Inelastic Neutron Scattering ◽  
Rotational Diffusion ◽  
Inelastic Neutron ◽  
Energy Dynamics ◽  
Line Characteristic ◽  
Methylene Groups ◽  
Orientational Ordering ◽  
Ordering Transition ◽  
Fcc Structure

ABSTRACTWe report neutron diffraction measurements of orientational ordering, and inelastic neutron scattering measurements of the inter- and intra-molecular excitations, for the 6:5 annulene isomer (C3 symmetry) of C61H2. We confirm previous x-ray measurements[1] which have shown that above 290K this isomer has an fcc structure, with the molecules orientationally disordered such that the methylene groups preferentially occupy “octahedral” sites. Below 290K, the diffraction pattern can be indexed on a simple cubic lattice, in direct analogy with the orientational ordering transition of C60. The observed low energy dynamics reflect this behavior. A peak corresponding to molecular librations is observed below the transition, at ∼2.5meV, while above the transition the peak collapses into a quasielastic line characteristic of rotational diffusion. The intramolecular spectra show several pronounced peaks. The assignments of these modes are discussed.

High frequency collective excitations in molten Fe/Ni alloys studied by inelastic neutron scattering

2008 ◽  
Vol 452 (1) ◽  
pp. 140-142 ◽  
Author(s):  
M. Jiménez-Ruiz ◽  
M.D. Ruiz-Martín ◽  
G.J. Cuello ◽  
R. Fernández-Perea ◽  
F.J. Bermejo
Keyword(s):  
Neutron Scattering ◽  
High Frequency ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Collective Excitations ◽  
Ni Alloys
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