Dynamic radial distribution function from inelastic neutron scattering
- Lujan Center, Los Alamos Neutron Science Center, Los Alamos National Laboratory, Los Alamos, New Mexico87545 (United States)
A real-space, local dynamic structure function g(r,{omega}) is defined from the dynamic structure function S(Q,{omega}), which can be measured using inelastic neutron scattering. At any particular frequency {omega}, S(Q,{omega}) contains Q-dependent intensity oscillations which reflect the spatial distribution and relative displacement directions for the atoms vibrating at that frequency. Information about local and dynamic atomic correlations is obtained from the Fourier transform of these oscillations g(r,{omega}) at the particular frequency. g(r,{omega}) can be formulated such that the elastic and frequency-summed limits correspond to the average and instantaneous radial distribution function, respectively, and is thus called the dynamic radial distribution function. As an example, the dynamic radial distribution function is calculated for fcc nickel in a model which considers only the harmonic atomic displacements due to phonons. The results of these calculations demonstrate that the magnitude of the atomic correlations can be quantified and g(r,{omega}) is a well-defined correlation function. This leads to a simple prescription for investigating local lattice dynamics. {copyright} {ital 1998} {ital The American Physical Society}
- OSTI ID:
- 627835
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 57, Issue 17; Other Information: PBD: May 1998
- Country of Publication:
- United States
- Language:
- English
Similar Records
Radial distribution of superthermal electrons measured with ECE (abstract)
Microscopic calculation of the dynamic structure function in the deep-inelastic regime