Electronic structure investigations of Ni and Cr films on (100)SrTiO3substrates using electron energy-loss spectroscopy

Metal/ceramic interfaces between thin nickel and chromium films and the TiO2terminated (100) surface of SrTiO3were studied by various transmission electron microscopy techniques to investigate the bonding behaviour between film and substrate. For the Ni/SrTiO3interface, a semi-coherent interface structure between three-dimensionally grown Ni islands and the SrTiO3substrate was observed. From electron energy-loss spectroscopy measurements and high-resolution transmission electron microscopy studies, the formation of a two-dimensional NiO layer at the interface was concluded, which dominates the adhesion between the Ni film and the ceramic substrate. At the Cr/SrTiO3interface, Cr –O bonds were found, possessing an ionic-bonding contribution. Comparing the bonding characteristics of Ni and Cr on the (100) surface of SrTiO3, a stronger adhesion of Cr than for Ni is proposed.