18O isotopic study of photo-induced formation of peroxide species on cubic Nd2O3

Photo-induced formation of peroxide species on cubic Nd2O3 was studied by in situ microprobe Raman spectroscopy using 18O as a tracer and a 325-nm laser as an excitation source. The results confirmed that the peroxide ions were formed through photooxidation of the lattice oxygen species in neodymium sesquioxide by molecular oxygen species. Under UV excitation (λ = 325 nm), the reaction between O2 and O2− could take place at room temperature. A fast oxygen exchange between the peroxide ions and the lattice oxygen species in Nd2O3 took place under the experimental conditions studied. Also, bulk lattice oxygen species in Nd2O3 could migrate to the surface layer and participate in the formation of peroxide ions. The migration of lattice oxygen species and the oxygen exchange between lattice oxygen and peroxide ions were promoted by UV laser irradiation.

Graphical AbstractPeroxide species can be generated through a photo-induced reaction between molecular oxygen and lattice oxygen of cubic neodymium sesquioxide. Both surface and bulk lattice oxygen species are involved in the formation of the peroxide species.Figure optionsDownload full-size imageDownload as PowerPoint slide