Atomic structures of planar defects in 0.95(Na0.5Bi0.5)TiO3–0.05BaTiO3 lead-free piezoelectric thin films

• NBT–BT films have been successfully prepared on polycrystalline Ni substrates.
• Planar defects related to the (Bi2O2)2+ layers are parallel to (1 0 0) plane of thin films.
• Complex planar defects contain edge-sharing TiO6 octahedra with the Bi cations residing in the cavities formed by the octahedral network.

Two types of planar defects are found in 0.95(Na0.5Bi0.5)TiO3–0.05BaTiO3 lead-free piezoelectric thin films prepared on polycrystalline Ni metal substrates. The atomic structures of these defects are characterized by means of aberration-corrected scanning transmission electron microscopy. The first type of planar defects is related to the (Bi2O2)2+ layers parallel to (1 0 0) plane of thin films. The second type of planar defects is determined as complex planar defects made up of edge-sharing TiO6 octahedra with the Bi cations residing in the cavities formed by the octahedral network. The formation of the Bi-rich defects is believed to affect the physical properties of the thin films.

Graphic abstract contains an atomic-resolution high-angle annular dark field image (left) and the structural model (right) of a novel type of planar faults in 0.95(Na0.5Bi0.5)TiO3–0.05BaTiO3 lead-free piezoelectric thin films.Figure optionsDownload as PowerPoint slide