Surface optical phonons in ZnO(Co) nanoparticles: Raman study

► Zno doped with CoO, two groups of different samples obtained. ► Coexistence of phases ZnCo2O4 and Co3O4 with ZnO registered by Raman spectroscopy. ► Existence of ZnO nanoparticles surface optical phonon. ► Changes of relative intensity ZnO and CoO modes have opposite character.