Fig. 1

Photographs, X-ray topographs, and rocking curves of BDD. a Morphology of the large-sized BDD with boron content (at.% B) in the crystal growth environment. b X-ray traverse topographs of the (001) BDD plates with boron concentration determined by the spark mass spectrometry and the Laue pattern of (111) plate with the boron concentration of ~2 × 10²⁰ cm⁻³ (far right). The sixfold symmetry indicates the presence of a twin. The additional small-sized spots are the satellites from a 2D incommensurately modulated structure. c The high-resolution double-crystal ω-scan rocking curves of BDD, CuKα₁ radiation, and Si(220) channel-cut monochromator. Panels a–c from top to bottom refer to the same crystal