Influence of Preparation Method on SOP Modes in ZnO Doped with CoO Nanoparticles

Abstract

The aim of the present work is to study influence of preparation method on samples characteristics, creation and behavior of surface optical phonons (SOP) modes with change of concentration of doping elements by micro Raman spectroscopy. Nanocrystalline samples of ZnO(Co) were prepared by use of traditional wet chemistry method followed by calcinations and the microwave assisted hydrothermal synthesis. The phase composition of the samples (ZnO, Co3O4, ZnCo2O4) and the mean crystalline size (14–300 nm) were determined using X-ray diffraction measurements. In this paper we report the experimental spectra of Raman scattering (from 100 to 1600 cm−1) for both type of samples. Main characteristic of experimental Raman spectrum are: sharp peak at 436 cm−1 and broad multi phonon structure at ~1150 cm−1, typical for ZnO; sharp peaks at 194, 482, 521, 618 and 691 cm−1 typical for Co3O4 and sharp peaks at 185, 475, 520, 610 and 690 cm−1 typical for ZnCo2O4 nanoparticles. The phonon of registered phase’s exhibit effects connected to phase concentration, while the SOP phonon mode exhibit significant confinement effect.