Characteristics of conductive SrRuO3 thin films with different microstructures

Conductive SrRuO3 thin films were epitaxially grown on (100) LaAlO3 substrates by pulsed laser deposition over a temperature range from 650 degrees C to 825 degrees C. Well-textured films exhibiting a strong orientation relationship to the underlying substrate could be obtained at a deposition temperature as low as 450 degrees C. The degree of crystallinity of the films improved with increasing deposition temperature as confirmed by x-ray diffraction, transmission electron microscopy, and scanning tunneling microscopy. Scanning electron microscopy revealed no particulates on the film surface. The resistivity of the SrRuO3 thin films was found to be a strong function of the crystallinity of the film and hence the substrate temperature during film deposition. A residual resistivity ratio (RRR = rho(300 K)/rho(4.2 K)) of more than 8 was obtained for the SrRuO3 thin films deposited under optimized processing conditions.