Effect of growth temperature on the microstructural properties of 0.95Na0.5Bi0.5TiO3–0.05BaTiO3 films prepared on MgO (0 0 1) substrates

• Published in: Materials letters Vol. 259; p. 126847
• Main Authors: Wu, Sheng-Qiang, Yun, Yi-Yang, Jin, Xiao-Wei, Cheng, Sheng, Liu, Kun, Liu, Ming, Lu, Lu, Cheng, Shao-Dong, Mi, Shao-Bo
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.01.2020; Elsevier BV
• Subjects: Defects; Electron microscopy; Epitaxial growth; Film growth; Heterostructures; Interfaces; Interfacial dislocations; Lead free; Magnesium oxide; Magnetron sputtering; Materials science; Microstructure; Piezoelectric films; Piezoelectric materials; Piezoelectricity; Substrates; Interfaces; Epitaxial growth; Piezoelectric materials; Electron microscopy; Defects
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2019.126847

•Lead-free (Bi0.5Na0.5)TiO3-BaTiO3 films epitaxially grow on MgO substrates.•Growth temperature affects the film/substrate orientation relationship.•Zigzag-type planar defects form in the films at high growth temperature.•Periodic dislocation arrays release film-substrate misfit strain. 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 (0 0 1)-oriented MgO substrates at 800 °C and 900 °C, respectively. By advanced electron microscopy techniques, the orientation relationship of (0 0 1)[1 1 0]film//(0 0 1)[1 0 0]MgO and (0 0 1)[1 0 0]film//(0 0 1)[1 0 0]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) 〈0 1 0〉 -type and (a/2) 〈011-〉 -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.