Optimal target-substrate distance in the growth of oxides thin films by pulsed laser deposition

A simple model to investigate the formation of the oxide phase during the growth of ternary oxides films by laser ablation deposition has been proposed. Since the crystallinity properties of the oxide films are subject to the oxygen stoichiometry, the model is based on the balance between the density of the oxygen and a characteristic density of the system, ɬ=3N0/L03, in order to scale the optimal target–substrate distance, L0. The interaction plume–laser is not considered. The model was applied for growing PbFe12O19 hexaferrite thin film, and it shows that the theoretical conditions found are near to the optimal ones for the film growth. According to the model, for a fixed oxygen pressure of 1.0 mbar and a substrate temperature of 700 °C, a target–substrate distance, L0≈3.1 cm, corresponding to a critical density of oxygen, ng=2.74Å~1015 cm-3, has been determined. The films show a high degree of c-axis orientation, high crystallographic quality and a proper stoichiometry.