Fixing Left and Right: Assignment of Chiral Elemental Crystal Structures using Kikuchi Diffraction

TL;DR

This paper demonstrates that Kikuchi diffraction in a scanning electron microscope can determine the chirality of elemental crystals like manganese, tellurium, and selenium, overcoming limitations of traditional X-ray diffraction methods.

Contribution

It introduces a novel application of dynamical Kikuchi diffraction for resolving the chirality of single-element crystal structures.

Findings

Kikuchi diffraction can detect local chirality in elemental crystals.

Chirality assignment was successfully demonstrated for β-manganese.

The method determines the sense of chirality in tellurium and selenium crystals.

Abstract

Crystals of the chemical elements manganese, tellurium, and selenium can show the effects of handedness. In order to sense the possible effects of a changing sense of chirality on the properties of samples from these elements, the potential presence of two, enantiomorphic, physically different, variants of these elemental crystal structures needs to be resolved in crystallographic analyses. Due to fundamental limitations of kinematical X-ray scattering in crystals, however, the effects of chirality in single-element crystals are very difficult to sense using standard X-ray diffraction techniques. In the present paper, we show that dynamical Kikuchi diffraction in the scanning electron microscope is sensitive to the local sense of chirality in crystals of single chemical elements. We demonstrate chirality assignment in $\beta$-manganese, and we determine the sense of crystal chirality from Kikuchi diffraction patterns of the trigonal structures of tellurium and selenium.