Effect of oxygen vacancies on the structural and transport properties of SrTiO3 thin films: experiments and ab-initio calculations

Abstract

This PhD Thesis studies the effect of oxygen vacancies on the structural and transport properties of SrTiO3 thin films under different degrees of epitaxial strain. The Thesis presents a novel approach combining experiments and ab-initio simulations to investigate and understand the underlying mechanisms that link oxygen vacancies and properties of this material. We determine the formation enthalpy and diffusion coefficient of oxygen vacancies as a function of strain. Moreover, we study by means of ab-initio calculations the influence of the different octahedral configurations, strain and oxygen vacancies on the ferroelectricity of the SrTiO3 thin films. Finally, the transport properties of the SrTiO3 thin films are also investigated in detail, discussing the similarities with the phenomenology observed in the famous LaAlO3/SrTiO3 interface.