X-ray diffraction (XRD) and scanning micro-XRD on heteroepitaxial micro-crystals

- experiments at European synchrotrons (ESRF etc.)
- determination of lattice tilt, lattice parameters, local strain variation, theoretical calculation of x-ray scattered intensity and strain status
- investigation of heteroepitaxial nano- and micro-strucrtures, defects (large areas of ordered 3D micro-crystals, Si, Ge, GaAs)
- several scanning x-ray microdiffraction experiments at synchrotron sources have been recently performed in collaboration with ETH Zurich and Politecnico di Milano.

Scanning micro-XRD on Ge micro-crystals:

Array of Ge 3D micro-crystals as well as isolated individual crystal grown on patterned Si substrate have been probed recently at ID01 at ESRF. The technique allowed us to prove that the thermal strain heals towards the top and upper part of crystal tower is defect free. Dislocations are expelled already close to the interface and the net tilt of crystals is formed at the bottom.

Falub, C. V., Meduňa, M., Chrastina, D., Isa, F., Marzegalli, A., Kreiliger, T., Taboada, A. G., Isella, G., Miglio, L., Dommann, A. & von Känel, H. (2013). Sci. Rep., 3, 2276.
http://www.nature.com/srep/2013/130724/srep02276/full/srep02276.html.

Scanning micro-XRD on SiGe multiple quantum well:

Individual SiGe 3D microcrystal overgrown by Ge/SiGe superlattice was probed at ID01 at ESRF in order to study crystalline quality of the multilayer locally. Top crystal facets of the microcrystal were scanned by x-ray beam and facet shape, periodicity and crystal quality were obtained locally from 3D reciprocal space map.

Meduňa, M., Falub, C. V., Isa, F., Chrastina, D., Kreiliger, T., Isella, G., and von Känel H. (2014). J. Appl. Cryst., 47, 2030.
http://journals.iucr.org/j/issues/2014/06/00/rg5079/index.html.