Pulsed Laser Deposition of (Sr1-xCa)RuO3 and Sr(Ru1-xTix)O3 Thin Films by Sequential Multilayer Process

ABSTRACTWe report on the growth and properties of (Sr1-xCax)Ru03 and Sr(Ru1-xTix)O3 thin films obtained by pulsed laser deposition. A sequential deposition of sub-monolayers from SrTiO3 and CaRuO3 end members has been successfully used to substitute Ca- and Ti- in the SrRuO3 perovskite structure. Magnetization measurements as well as transport properties exhibit very different behavior for each type of substitution. In the case of Ca- substituted samples, the resistivity remains metallic and is consistent with the expected behavior for intermediate compositions. A progressive reduction of the Curie temperature with higher doping is reported. In the case of Ti- substituted samples, we observe a stronger reduction of the Curie temperature and remanent magnetization with increasing Ti substitution. Resistivity as a function of temperature shows a crossover from metallic to semiconducting behavior with variable range hopping process for a high level of Ti doping and points out the clear differences between the two substitutions sites. In both cases, the observed reduction of the magnetization with increasing doping concentration can be well described by assuming a random distribution of substituted sites in the perovskite structure.