1.
J Synchrotron Radiat
; 26(Pt 3): 819-824, 2019 May 01.
Article
in English
| MEDLINE
| ID: mdl-31074447
ABSTRACT
The covalent electron density, which makes Si(222) measurable, is subject to laser excitation. The three-wave Si(222)/(13 {\overline 1}) diffraction at 7.82â keV is used for phase measurements. It is found that laser excitation causes a relative phase change of around 4° in Si(222) in the first 100â ps of excitation and this is gradually recovered over several nanoseconds. This phase change is due to laser excitation of covalent electrons around the silicon atoms in the unit cell and makes the electron density deviate further from the centrosymmetric distribution.