Microstructure and Electrical Conductivity of BaRuO₃ Thin Films Prepared by Laser Ablation

Abstract

BaRuO₃ (BRO) thin films were prepared by laser ablation at substrate temperature (T_sub) ranging from room temperature to 973 K in a high vacuum (10⁻⁶ Pa) and in O₂ at oxygen pressures (P_O2) of 0.13 to 130 Pa. The relationship between deposition conditions, microstructure, binding state and electrical conductivity was investigated. 9R-type BRO thin film with well-crystallized fine grains was obtained at P_O2=13 Pa and T_sub>773 K. BaRu₆O₁₂ was co-deposited with BRO at P=10⁻⁶ Pa and T_sub>573 K. The electrical conductivity (σ) of the BRO thin films positively correlated with T_sub and P_O2. Highly conductive (σ>10⁴ S·m⁻¹) BRO thin films showed metallic conduction whereas less conductive (σ<10⁴ S·m⁻¹) BRO thin films showed semiconducting behavior. BRO thin film prepared at P_O2=13 Pa and T_sub=773 K exhibited a maximum σ of 7.7×10⁴ S·m⁻¹ at room temperature.