Large piezoelectricity in NaNbO3-based lead-free ceramics via tuning oxygen octahedral tilt

Lu Wang; He Qi; Botao Gao; Ye Liu; Hui Liu; Jun Chen

doi:10.1039/d1mh01680f

Large piezoelectricity in NaNbO₃-based lead-free ceramics via tuning oxygen octahedral tilt

Mater Horiz. 2022 Mar 7;9(3):1002-1009. doi: 10.1039/d1mh01680f.

Authors

Lu Wang^{1

2}, He Qi^{1

2}, Botao Gao^{1

2}, Ye Liu^{1

2}, Hui Liu^{1

3}, Jun Chen^{1

2}

Affiliations

¹ Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China. [email protected].
² Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China.
³ School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China.

PMID: 34985083
DOI: 10.1039/d1mh01680f

Abstract

The development of high-performance lead-free piezoceramics for replacing Pb-based perovskites has attracted lots of attention, and comparable room-temperature piezoresponse has been realized in (Na,K)NbO₃ and BaTiO₃-based ceramics with local structure heterogeneity via adjusting polymorphic phase boundary. In this work, a new method of oxygen octahedron tilt design is used in NaNbO₃-based lead-free ceramics, which usually shows complex oxygen octahedron tilt information inherited from NaNbO₃. The substitution of Ba(Fe_0.5Nb_0.5)O₃ and BaTiO₃ with high tolerance factor into NaNbO₃ leads to a gradual elimination of anti-parallel cation displacement and anti-phase tilt along the three axes; as a result, a single tetragonal phase with P4bm space group and only in-phase tilt along c axis is achieved in 0.88NaNbO₃-0.04Ba(Fe_0.5Nb_0.5)O₃-0.08BaTiO₃ ceramic. Accompanying the decreased oxygen octahedral tilt degree, a drastically improved d₃₃ up to 367 pC N^-1 (over ten times that of NaNbO₃ ceramic) is obtained, reaching a record high in NaNbO₃-based lead-free ceramics. Together with temperature insensitive piezoresponse originating from thermally stable oxygen octahedral tilt structure, the studied NaNbO₃-based materials show large potential for replacing Pb-based ceramics in some electronic devices. The oxygen octahedron tilt engineering would be used for designing more high-performance lead-free ceramics with high piezoresponse and excellent thermal stability simultaneously.