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Abstract Dislocations in chemical vapor deposited (111) single crystal diamond were studied by synchrotron X-ray topography. By analyzing X-ray topography images with various g vectors using the contrast extinction criterion, mixed dislocations with b = a/2 [011] and edge dislocations with b = a/2 [0 1 ¯ 1] are determined. Then, etch pits were formed using O 2 /H 2 plasma; observations by X-ray topography and atomic force microscopy revealed that etch pits formed on the dislocations. Hence, we investigated the relationship between the types of dislocations structure and the formation of etch pits. The results showed that the etch pits were larger in diamond samples with mixed dislocations than in those of edge dislocations. Graphical abstract Unlabelled Image Highlights • Dislocations and etch pits in chemical vapor deposited (111) single crystal diamond were studied. • Dislocations are determined as pure edge dislocation and mixed dislocations. • Etch pits on mixed dislocations are larger than in those of edge dislocations. [ABSTRACT FROM AUTHOR]

The effects of thermal annealing on stacking faults and dislocations in single-crystal diamonds with a low defect density were investigated by synchrotron X-ray topography. We compared the X-ray topography images before and after annealing under various diffraction conditions. We found that the stacking faults disappeared after annealing, and new dislocations appeared at the edges of disappeared stacking faults. These results indicate that the stacking faults were Shockley type, and they were sandwiched between two Shockley partial dislocations. Therefore, we concluded that the Shockley stacking faults disappeared as a result of the movement of the Shockley partial dislocations. Before annealing, the perfect dislocations were straight along the [2 1 ¯ 1] direction; annealing caused these dislocations to bend along the [1 1 ¯ 0] and [101] directions. We identified two dislocation shapes; upper bending and lower bending dislocations. An analysis based on contrast extinction criterion; indicated that the bending direction depends on the Burgers vector, for example, a dislocation with b = a/2[101] moved along the [0 11 ¯ ] direction, and a dislocation with b = a/2[1 1 ¯ 0] moved along the [011] direction. [ABSTRACT FROM AUTHOR]