Extension of the time-dependent dynamical diffraction theory to 'optical phonon'-type distortions: application to diffraction from coherent acoustic and optical phonons.

Journal article

An extension of the time-dependent Takagi-Taupin theory to 'optical phonon'-type distortions is presented. By splitting the susceptibility into the contributions from each atom in a unit cell, modifications to the structure factor as well as lattice parameter are taken into account. The result is a compact, surprisingly simple, equation with a strong formal similarity to the classical Takagi-Taupin equation, with the latter included as a special case. Time dependence is explicitly retained and thus the analysis is applicable to situations where the crystal is modified on time scales comparable with that for the X-rays to traverse an extinction depth. A comparison is made between the influence of coherent acoustic and optical phonons on the diffraction of X-rays. Numerical and perturbative analytical solutions of the generalized Takagi-Taupin equation are presented in the presence of such phonons.

Authors: Sondhauss, P; Wark, J

• Publication status: Published
• Journal: Acta crystallographica. Section A, Foundations of crystallography
• Volume: 59
• Issue: Pt 1
• Pages: 7-13
• Publication date: 2003-01-01
• DOI: 10.1107/S010876730201704X
• EISSN: 1600-5724
• ISSN: 0108-7673
• Language: English