Effect of growth temperature on the microstructural properties of 0.95Na0.5Bi0.5TiO3–0.05BaTiO3 films prepared on MgO (001) substrates

Abstract Lead-free 0.95(Na0.5Bi0.5)TiO3–0.05BaTiO3 (NBT–BT) piezoelectric films have been successfully fabricated by high-pressure magnetron sputtering deposition technique on (001)-oriented MgO substrates at 800 °C and 900 °C, respectively. By advanced electron microscopy techniques, the orientation relationship of (001)[110]film//(001)[100]MgO and (001)[100]film//(001)[100]MgO is determined for the NBT–BT/MgO heterostructures prepared at 800 °C and 900 °C, respectively. In comparison, a high density of zigzag-typed planar defects appear in the film prepared at 900 °C. At the semi-coherent interfaces, periodic dislocation arrays form to relax the film-substrate misfit strain. In particular, the formation of both (a/2) -type and (a/2) 1 - >-type interfacial dislocations facilitates the growth of NBT–BT films on rough MgO substrates at 900 °C. Our findings indicate that the mode of film growth and microstructure for NBT–BT films prepared on MgO substrates can be tuned by the growth temperature.