X-ray diffraction from hexagonal dislocation networks

Abstract

We built the honeycomb networks of misfit dislocations by combining angular dislocations. Two different models of the disorder in the dislocation network are explored, the random shifts of nodes and random sources of distortion. The displacement fields of disturbed dislocation networks are used to simulate the X-ray diffraction patterns by Monte Carlo method. We find that substantial disorder is needed for random shifts to be experimentally observable as diffuse scattering. The model of random distortion sources produces comparable diffuse scattering with the dislocation network looking closer to the initial perfect structure. The diffraction patterns due to distorted honeycomb dislocation networks are compared with the ones due to triangular networks of straight dislocations. The disorder parameters of the latter networks can be chosen to produce diffraction patterns similar to the former.

Keywords:

• honeycomb structure
• misfit dislocations
• X-ray diffraction

Acknowledgements

The authors thank A. Yu. Belov and B. Jenichen for critical reading of the manuscript.

Additional information

Funding

This work has been funded by Deutsche Forschungsgemeinschaft (DFG) [grant number KA 3262/2-2].