Castillo Sarah M, Tang Zhongjia, Litvinchuk Alexander P, Guloy Arnold M
Department of Chemistry and Texas Center for Superconductivity, University of Houston , Houston, Texas 77204-5003, United States.
Department of Physics and Texas Center for Superconductivity, University of Houston , Houston, Texas 77204-5002, United States.
Inorg Chem. 2016 Oct 17;55(20):10203-10207. doi: 10.1021/acs.inorgchem.6b01399. Epub 2016 Sep 26.
The structures of two trigonal-rhombohedral CaSi polymorphs (space group R3̅m) were studied by X-ray diffraction and polarized Raman scattering spectroscopy. Raman-active even-parity vibrational modes of A and E are unambiguously identified and assigned to the specific lattice eigenmodes. Experimental data are found to be in very good agreement with those predicted by density functional theory lattice dynamics calculations. The transformation of 6R structural modification of CaSi into its 3R polymorph, by high-temperature annealing in vacuum is also reported.
