Shallow nitrogen acceptor in TiO2 studied by β-NMR spectroscopy

Abstract The local electronic structure of substitutional nitrogen impurity in rutile TiO 2 was studied by means of the β-NMR technique. A short-lived β emitter 12 N ( I =1, T 1/2 =11 ms) was implanted into a rutile single crystal as a probe nucleus to detect double-quantum NMR spectrum. The result shows the existence of a small hyperfine interaction at low temperatures due to paramagnetic states localized at oxygen substitutional site, which suggests that a substitutional nitrogen atom acts as a shallow acceptor in rutile TiO 2 .