Abstract
We present a methodology to extract the single-crystal phonon dispersion from polycrystalline materials. The approach consists of recording inelastic x-ray scattering (IXS) spectra over a large momentum transfer region (typically ), and confront them with a model calculation which properly takes into account the polycrystalline state of the material and the IXS cross section. A least-squares refinement of the model spectra then provides the single-crystal dispersion scheme. For the benchmark cases beryllium and graphite we demonstrate that very good agreement with available single-crystal phonon dispersions is obtained. Furthermore, we show for the case of graphite that a simple texture can be properly taken into account. The proposed method promises to be a valuable tool in cases where single-crystalline materials are not available.
1 More- Received 23 September 2008
DOI:https://doi.org/10.1103/PhysRevB.79.134302
©2009 American Physical Society