Structure and electronic properties of imperfect oxides and nanooxides

Abstract

Results of studies of the structure and physicochemical properties of perfect (defectless) and imperfect (containing point defects) nanoparticles of metal oxides by the methods of scanning tunnel microscopy (STM) and spectroscopy (STS) are summarized and reviewed. Using nanooxides of various metals (Al, Pt, W, and Ti), as examples, it was demonstrated that the modern STM and STS methods make it possible to measure the electronic spectra of perfect nanoparticles, detect individual and associated point defects, determine spatial distributions of defects, derive spatial and energetic distributions of electrons trapped on point defects (anionic vacancies, intercalation atoms, and adatoms), detect single electron spins (paramagnetic surface complexes), measure phonon and vibration spectra of individual nanoparticles and surface complexes, determine (from measured electronic and phonon spectra) the chemical composition and atomic structure of individual nanoparticles. It was emphasized that modern versions of the STM-STS methods can constitute the foundation of new analytical methods needed in nanometrology and nanodefectoscopy.