Direct determination of Burgers vector sense and magnitude of elementary dislocations by synchrotron white x-ray topography

The x-ray topography by using highly coherent beam obtained at third-generation synchrotron facilities can provide higher spatial resolution and higher lattice-distortion sensitivity than those by former-generation facilities. Here, we report the direct determination of the Burgers vector senses and magnitudes of elementary dislocations in a high-quality silicon carbide single crystal using white x-ray section topography with a long sample-to-film distance. Our data strongly indicate that there are very weak but extraordinarily long-range elastic interactions between elementary screw dislocations. Those interactions govern dislocation-propagation behavior and the distribution of dislocations. Moreover, we found that white x-ray projection topography with a long sample-to-film distance can also be a powerful tool to effectively examine the detailed structure of elementary dislocations in single crystals.