Preparation and characterization of Zn18O/Zn16O isotope heterostructure thin films

An oxygen isotope-based heterostructure zinc oxide (ZnO) thin film, Zn16O/Zn18O/Zn16O, was made by pulsed laser deposition on an a-face sapphire substrate. The isotope-enriched Zn18O layer was made by irradiation of the isotope oxygen radical (18O*). The isotopic ratio in the heterostructure film was analyzed via secondary ion mass spectroscopy (SIMS). The ratio of exchange from 16O to 18O was approximately 70% when the oxygen isotope was irradiated as a radical, while it was approximately 10% when the oxygen isotope was supplied as 18O2 gas.