Investigation of the Polytypism in Layered CdInGaS4 Crystals by Electron Diffraction Methods

The polytypism in layered CdInGaS 4 crystals grown by chemical transport reaction has been investigated by previously developed methods of oblique-texture electron diffraction and electron diffraction rotation for single crystals. It is shown that, along with the known 1 T , 2 H , and 3 R polytypes, the 3 T and 6 R polytypes are identified incorrectly when using oblique-texture electron diffraction. A single-crystal rotation study revealed that the 3 T polytypes are mixtures of the 1 T and 3 R polytypes and the 6 R polytypes are mixtures of the 2 H and 3 R polytypes. Different polytypes alternate strictly in the direction perpendicular to the layers. The advantages of the electron diffraction rotation in comparison with other diffraction methods in phase and structural diagnostics of polytype mixtures are shown.