Phonons from neutron powder diffraction

Article

关键词: LATTICE-DYNAMICS;    CALCIUM-FLUORIDE;    SCATTERING;   

DOI  :  10.1103/PhysRevB.60.6204

来源: SCIE

【 摘 要 】

The spherically averaged structure function S(\q\)obtained from pulsed neutron powder diffraction contains both elastic and inelastic scattering via an integral over energy. The Fourier transformation of S(\q\) to real space, as is done in the pair density function (PDF) analysis, regularizes the data, i.e., it accentuates the diffuse scattering. We present a technique which enables the extraction of off-center (\q\not equal 0) phonon information from powder diffraction experiments by comparing the experimental PDF with theoretical calculations based on standard interatomic potentials and the crystal symmetry. This procedure [dynamics from powder diffraction] has been successfully implemented as demonstrated here for two systems, a simple metal fee Ni and an ionic crystal CaF2. Although computationally intensive, this data analysis allows for a phonon based modeling of the PDF, and additionally provides off-center phonon information from neutron powder diffraction, [S0163-1829(99)05733-1].

【 授权许可】

Free