Effects of substrate temperature on the growth and properties of SrRuO3and CaRuO3 thin films

We report the observation of a low-temperature secondary growth orientation in SrRuO3 thin films grown on LaAlO3 substrates by pulsed laser deposition. This growth phase is present in crystalline films grown at substrate temperatures below similar to 600 degreesC and occurs in combination with the standard (110) oriented growth observed in films grown at higher temperatures. This secondary growth orientation does not occur in films of CaRuO3 grown on LaAlO3 at the same temperatures, presumably due to lattice mismatch considerations. We report for the first time the effects of the change in growth temperature from 200 to 800 degreesC on the orientation, lattice parameter, mosaicity and resistivity of both SrRuO3 and CaRuO3 films. We also discuss the dependence of the ferromagnetic transition temperature in the SrRuO3 thin films on the growth temperature, as determined from the temperature dependence of the resistivity.