Mapping of individual dislocations with dark-field X-ray microscopy
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2019-02-01 |
| Journal | Journal of Applied Crystallography |
| Authors | Anders C. Jakobsen, Hugh Simons, Wolfgang Ludwig, Can Yildirim, Hanna Leemreize |
| Institutions | Technical University of Denmark, Danish Technological Institute |
| Citations | 55 |
Abstract
Section titled āAbstractāThis article presents an X-ray microscopy approach for mapping deeply embedded dislocations in three dimensions using a monochromatic beam with a low divergence. Magnified images are acquired by inserting an X-ray objective lens in the diffracted beam. The strain fields close to the core of dislocations give rise to scattering at angles where weak beam conditions are obtained. Analytical expressions are derived for the image contrast. While the use of the objective implies an integration over two directions in reciprocal space, scanning an aperture in the back focal plane of the microscope allows a reciprocal-space resolution of Ī Q / Q < 5 Ć 10 ā5 in all directions, ultimately enabling high-precision mapping of lattice strain and tilt. The approach is demonstrated on three types of samples: a multi-scale study of a large diamond crystal in transmission, magnified section topography on a 140 Āµm-thick SrTiO 3 sample and a reflection study of misfit dislocations in a 120 nm-thick BiFeO 3 film epitaxially grown on a thick substrate. With optimal contrast, the half-widths at half-maximum of the dislocation lines are 200 nm.