Raman scattering study of mixed metal oxide Ir$_{x}$Ru$_{1-x}$O$_{2}$ nanowires grown by chemical vapor deposition

We present Raman scattering results of mixed metal oxide Ir$_{x}$Ru$_{1-x}$O$_{2}$ nanowires that have been studied for their stability and for activity as electrocatalysts. For our study, 1-dimensional metallic mixed oxide single crystalline Ir$_{x}$Ru$_{1-x}$O$_{2}$ nanowires were synthesized, for the first time, via a simple physical vapor transport process by controlling relative ratios of two precursors, RuO$_{2}$ and IrO$_{2}$, respectively. We measured Raman spectra of Ir$_{x}$Ru$_{1-x}$O$_{2}$ nanowires using excitation laser sources with wavelengths of 488 nm and 632.8 nm. We observed that an E$_{g}$ phonon mode of an Ir$_{x}$Ru$_{1-x}$O$_{2}$ nanowire is being blue-shifted linearly with respect to the Ir contents. We could use our observation of frequency shift of the E$_{g}$ phonon to determine stoichiometry information of nanowires which we also measured and confirmed by using EDS. From the shape of the phonon modes we measured, we could get information regarding crystalline quality that was also measured by HRTEM. We show that Raman scattering spectroscopy can provide a simple, prompt, and effective mean to measure the stoichiometry and crystalline quality of mixed metal oxide nanowires.