Interfacial structure of epitaxial SrTiO3 on Si: experiments and simulations

The interfacial structure of epitaxial SrTiO3 (STO) on Si has been investigated using combined experimental and theoretical approaches. Together with high resolution high angle annular dark field image, spatially resolved electron energy loss spectroscopy (EELS) acquired across the STO/Si interface reveals an interfacial region of 1-2 monolayer thickness, which is lacking in Sr, but contains Ti, Si and O. General agreement exists between the experimental EELS results and the simulated ones, which are obtained based on a classical molecular dynamics interface model, disclosing a gradual change in the local atomic coordination symmetry and possible defect incorporation at the interface.