title: Identification of A- and B-site cation vacancy defects in perovskite oxide thin films.
abstract: Cation vacancies on both sublattices (V(Ti), V(Sr)) have been identified in homoepitaxial pulsed laser deposited SrTiO3 films using high intensity variable energy positron annihilation lifetime spectroscopy (PALS) measurements. Film nonstoichiometry was varied by varying laser fluence. PALS showed that on increasing the fluence above the Ti/Sr∼1 value, the concentration ratio [V(Sr)]/[V(Ti)] systematically increased. Reducing the fluence into the Ti-poor region below resulted in additional vacancy cluster defect formation. Vacancy concentrations greater than ∼50  ppm were observed in all films.
authors.affiliation: Carnegie Laboratory of Physics, School of Engineering, Physics, and Mathematics, University of Dundee, Dundee DD1 4HN, United Kingdom. d.j.keeble@dundee.ac.uk
authors.forename: D J
authors.initials: DJ
authors.lastname: Keeble
authors.forename: S
authors.initials: S
authors.lastname: Wicklein
authors.forename: R
authors.initials: R
authors.lastname: Dittmann
authors.forename: L
authors.initials: L
authors.lastname: Ravelli
authors.forename: R A
authors.initials: RA
authors.lastname: Mackie
authors.forename: W
authors.initials: W
authors.lastname: Egger