Structural transformations and desirable electronic properties of low-temperature grown ruthenium oxide films under nitrogen atmosphere

Abstract Sr2RuO4 has recently attracted intense attentions for its intriguing physical properties. However, the ultra-high growth temperature (≥1000 °C) poses a major challenge for fabricating high-quality Sr2RuO4 films. In sharp contrast to effort previously attempted in traditional oxygen atmosphere, herein, a nitrogen gas is employed to grow ruthenium oxide films during pulsed laser depositions (PLD). It is shown that the present method facilitates a successive SrRuO3–Sr2RuO4 structural transformation via increasing growth temperatures from 700 °C to 900 °C. The high-quality Sr2RuO4 film grown at a relative low deposition temperature exhibits a comparable electrical resistivity, in comparison with counterparts deposited at oxygen atmosphere. Combined X-ray photoelectron and X-ray absorption measurements suggest that the nonreactive nitrogen atmosphere involved during the deposition yields a relative lower kinetic energy of laser ablated plume reaching to substrates, and effectively regulates structural and electronic properties of ruthenium oxide films. These findings may offer a new route for synthesizing other oxide functional films with high deposition-temperature.