Local conductivity of epitaxial Fe-doped SrTiO3thin films

Atomic Force Microscopy (AFM) measurements have been performed for Fe-doped SrTiO3 thin films with an Fe concentration of 1 and 2 at%. Thin films with a thickness of 15–50 nm were grown by pulsed laser deposition on single crystalline SrTi0.99Nb0.01O3 substrates. Low-energy electron diffraction examination showed that the films are single crystalline. The regions treated with the AFM tip (applied dc voltage up to 6 V) showed inhomogeneity of the electrical conductivity. Resistive switching was studied by the use of local conductive atomic force microscopy and was present in all samples. Fe doping was found to influence the character of switching.