Formation probability for enantiomorphic crystals (with the space groups of P6 222 and P6 422) in transition-metal disilicides with the C40 structure as determined by convergent-beam electron diffraction

Abstract

The new CBED (convergent-beam electron diffraction) method we proposed recently for enantiomorph identification has successfully been applied to polycrystals of TaSi 2 and NbSi 2 with the C40 structure in order to determine the probability for the formation of enantiomorphic crystals (those belonging to the space groups of P6 222 and P6 422). To the best of the authors' knowledge, this is the first assessment for the formation probability of enantiomorphic crystals for optically opaque inorganic crystals. Although the formation probability varies from sample to sample, it tends to be statistically equal for the enantiomorphic pairs of crystals as the number of samples investigated increases, in agreement with other results so far obtained for many organic crystals.