Microstructural and conductive properties of BaRuO3 thin films

We have grown conducting BaRuO3 films on (100) LaAlO3 substrate using pulsed laser deposition technique over temperature range varying from 500 to 775 °C. The films are well textured and are c-axis oriented with an in-plane epitaxial relationship of 〈010〉〈100〉BaRuO3∥〈110〉 LaAlO3. Atomic force microscopy observation shows that they consist of a fine arranged network of grains and have a mosaic microstructure. Surfaces with smooth terraces have been observed by Scanning Tunneling Microscopy. The resistivity of the films has been found to be a strong function of substrate temperature during film deposition. Both metallic and semiconducting behaviour has been observed in these films. Temperature-dependence resistivity measurement shows that the film has a metallic curve if it is deposited at 700 °C or lower but it transfers to a semiconducting-metallic twofold curve if the deposition temperature is increased. This unique phenomenon, which is not observed in bulk, may provide new features useful in the fabrication of novel electronic devices.