Effect of Ba substitution on the microstructure and electrical conductivity of Ba_xCa_1-xRuO₃ thin films prepared by laser ablation

Ba_xCa_1-xRuO₃ (BCRO) thin films were prepared by laser ablation on quartz substrates at a substrate temperature (T_sub) of 973 K and an oxygen pressure (Po₂) of 13 Pa. The effect of Ba substitution on the microstructure and electrical conductivity (σ) was investigated. Rectangular-shaped CaRuO₃ (CRO) island grains grew in BCRO thin films at a Ba fraction (x) below 0.1. BCRO thin films prepared at x > 0.2 consisted of fine grains. BCRO thin films at x > 0.2 showed metallic conduction, whereas those with an island structure at x < 0.1 showed semi-conducting behavior. The σ increased from 2.5 × 10 ³ S·m^-1 to 3.8 × 10⁴ S·m^-1 with increasing x from 0.1 to 1.0.