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A realization of excellent piezoelectricity and good thermal stability in CaBi 2 Nb 2 O 9 : Pseudo phase boundary
Author(s) -
Liu Gang,
Wang Dan,
Wu Chao,
Wu Jiagang,
Chen Qiang
Publication year - 2019
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.16033
Subject(s) - piezoelectricity , phase boundary , materials science , curie temperature , thermal stability , bismuth , ceramic , condensed matter physics , ferroelectricity , mineralogy , phase (matter) , optoelectronics , composite material , chemistry , physics , metallurgy , dielectric , ferromagnetism , organic chemistry
Phase boundaries (PBs) are known to contribute to the outstanding performances of lead‐based and lead‐free materials. However, a lack of PBs restricts the promotion of piezoelectric performance in bismuth layer‐structured ferroelectrics (BLSFs). In this work, a pseudo PB, ie, pseudotetragonal distortion (regulated by Ce), is proposed to promote the piezoelectric properties of CaBi 2 Nb 2 O 9 ‐based ceramics, and an excellent piezoelectric constant ( d 33 ) of 20.2 pC/N with a high Curie temperature of 923°C is obtained. Verified Ce incorporation into the (Bi 2 O 2 ) 2+ layer alters the environment of the (Bi 2 O 2 ) 2+ layer, thereby influencing the atomic displacement in the Nb‐O octahedron and modulating the theoretical spontaneous polarization ( P s ). Strengthening of the pseudotetragonal distortion is favorable to the polarization switching, and maintains the theoretical P s of ceramics at a high level, thus realizing the promotion of d 33 . Furthermore, pseudotetragonal distortion guarantees good thermal depoling performance of the ceramic, which remains at 89.6% (18.1 pC/N) of its initial d 33 after depoling at 875°C. This work provides clear guidance on obtaining high d 33 and good thermal stability in BLSFs.