Determining alloy composition in MoxW(1-x)S2 from low wavenumber Raman spectroscopy

Mixed alloy MoxW(1-x)S2 (0x1) bulk samples are characterized by low wavenumber Raman spectroscopy. The results provide a convenient and reliable means for systematically determining the sample Mo/W composition. The absence of disorder effects in its interlayer motion (unlike for the intralayer motion) and the lack of Mo/W composition dependence of the shear mode force constants enable the facile employment of a reduced monoatomic linear chain model by treating the bulk alloy as a series of single balls' of mass (xm(Mo)+(1-x)m(W)+2m(S))attached by interlayer springs with a composition-independent interlayer force constant of 2.52Nm. Shear mode Raman scattering analysis may consequently be complementary to the electronic spectroscopy tools (X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDS)), commonly used for mixed alloy bulk composition characterization. Copyright (c) 2017 John Wiley & Sons, Ltd.