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Defect suppression in CaZrO 3 ‐modified (K, Na)NbO 3 ‐based lead‐free piezoceramic by sintering atmosphere control
Author(s) -
Thong HaoCheng,
Li Qi,
Zhang MaoHua,
Zhao Chunlin,
Huang Kevin Xiu,
Li JingFeng,
Wang Ke
Publication year - 2018
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.15488
Subject(s) - sintering , piezoelectricity , materials science , atmosphere (unit) , ceramic , mineralogy , oxygen , reducing atmosphere , composite material , analytical chemistry (journal) , chemical engineering , metallurgy , chemistry , thermodynamics , physics , organic chemistry , chromatography , engineering
During high‐temperature crystal growth, lattice defects will inevitably form inside piezoelectric materials, which can be a hindrance for performance optimization. Through appropriate atmosphere control during sintering, defect levels inside the piezoelectric material can be regulated. Herein, CaZrO 3 ‐modified (K, Na)NbO 3 ‐based lead‐free piezoelectric ceramics with a nominal composition of 0.95(Na 0.49 K 0.49 Li 0.02 )(Nb 0.8 Ta 0.2 )O 3 ‐0.05CaZrO 3 are produced by sintering in an oxygen‐rich atmosphere. Compared with an air‐sintered sample, the piezoelectric constant of the oxygen‐sintered sample has greatly improved 15% up to 390 pC/N, which is comparable to commercial lead‐based counterparts. In addition, the planar electromechanical coupling factor k p is enhanced from 0.46 to 0.52. A qualitative model related to defect engineering is proposed to support the experimental observations. Our results indicate the feasibility of purposely optimizing the piezoelectric performance by sintering atmosphere control.