Raman scattering study of IrxRu1−xO2 mixed metal oxide nanowires (0 ≤ x ≤ 1)

Recent interests in mixed metal oxide nanostructured materials especially IrxRu1−xO2 compounds have been mainly driven by the technological application as electrocatalyst and electrode materials. We present room temperature Raman scattering results of single crystalline IrxRu1−xO2 (0 ≤ x ≤ 1) nanowires grown by atmospheric pressure chemical vapor deposition. We observed that the Eg, the A1g, and the B2g phonon modes of a single IrxRu1−xO2 nanowire are blue-shifted linearly with respect to the Ir contents from which we could get stoichiometry information. We also observed that the asymmetric lineshape and the broadening of the full width at half maximum of the Eg mode that involves the out-of-plane oxygen vibration. The unusual asymmetric broadening of the Eg phonon can be explained by the activation of the non-zone-center phonons due to substitutional disorder present in the system. We also found that there is a mixed mode of the A1g and the B2g phonons due to the substitutional disorder, in the range of 630-750 cm−1.