Stress Dependence of Crystal Structure of Polycrystalline BiFeO3 Thin Films on Membrane Structure Prepared by Pulsed Laser Deposition

An Influence of stress of crystal structure of polycrystalline BiFeO3 (BFO) thin film on membrane structure has been investigated. To confirm the stress dependence of the crystal structure, reciprocal space mapping measurement of polycrystalline BFO thin films on Pt (200 nm)/TiO2 (50 nm)/SiO2 (600 nm)/Si (625 μm) plate substrate and Pt (200 nm)/TiO2 (50 nm)/SiO2 (600 nm)/Si (15 μm) membrane substrate have been performed. These BFO thin films have been prepared by pulsed laser deposition (PLD). The obtained BFO thin films were polycrystalline and mainly oriented to (001) and (110) plane. From reciprocal space mapping measurement, (110) oriented BFO grains on Pt/TiO2/SiO2/Si (15 μm) membrane substrate were expanded perpendicularly to the film plane about 0.15% and compressed in parallel to the film plane about 0.7% comparing to that on Pt/TiO2/SiO2/Si (625 μm) plate substrate. And (001) oriented BFO grains on the Pt/TiO2/SiO2/Si membrane substrate were expanded about 0.20% perpendicularly to the film plane and compressed about 1.3% in parallel to the film plane comparing to that on Pt/TiO2/SiO2/Si (625 μm) plate substrat