Graphene-like conjugated pi-bond system in Pb1-xSnxSe
Abstract
Following the identification of the pi bond in graphene, in this work, a pi bond constructed through side-to-side overlap of half-filled 6pz orbitals was observed in a non-carbon crystal of Pb1-xSnxSe (x=0.34) (PSS), a prototype topological crystalline insulator (TCI) and thermoelectric material with a high figure-of-merit (ZT). PSS compounds with a rock-salt type cubic crystal structure was found to consist of sigma bond connected covalent chains of Pb(Sn)-Se with an additional pi bond that is shared as a conjugated system among the four nearest neighbor Pb pairs in square symmetry within all (001) monoatomic layers per cubic unit cell. The pi bond formed with half-filled 6pz orbitals between Pb atoms is consistent with the calculated results from quantum chemistry. The presence of pi bonds was identified and verified with electron energy-loss spectroscopy (EELS) through plasmonic excitations and electron density (ED) mapping via an inverse Fourier transform of X-ray diffraction.
Keywords
Cite
@article{arxiv.1503.06946,
title = {Graphene-like conjugated pi-bond system in Pb1-xSnxSe},
author = {G. J. Shu and S. C. Liou and S. Karna and R. Sankar and M. Hayashi and M. -W. Chu and F. C. Chou},
journal= {arXiv preprint arXiv:1503.06946},
year = {2015}
}
Comments
5 pages, 4 figures, to be published in Appl Phys. Lett