Effect of Ba Substitution on the Microstructure and Electrical Conductivity of Ba_xCa_1−xRuO₃ Thin Films Prepared by Laser Ablation

Abstract

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 (P_O2) 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 2.5×10³ S·m⁻¹ to 3.8×10⁴ S·m⁻¹ with increasing x from 0.1 to 1.0.