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Effect of A Site Substitution on the Properties of CaBi 2 Nb 2 O 9 Ferroelectric Ceramics
Author(s) -
Zhang Xiaodong,
Yan Haixue,
Reece Michael J
Publication year - 2008
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/j.1551-2916.2008.02564.x
Subject(s) - aurivillius , materials science , curie temperature , electrical resistivity and conductivity , ferroelectricity , dopant , ceramic , analytical chemistry (journal) , sintering , mineralogy , doping , condensed matter physics , metallurgy , dielectric , chemistry , ferromagnetism , physics , optoelectronics , engineering , chromatography , electrical engineering
The effect of A‐site substitution on the piezoelectric coefficient, high‐temperature dc resistivity, and thermal depoling behavior of Aurivillius phase CaBi 2 Nb 2 O 9 ferroelectric ceramics was investigated. Ceramics with the general formula of Ca 1− x M x Bi 2 Nb 2 O 9 , where M=Na, (Na,Ce), (Na,La), and La, were prepared by conventional solid‐state sintering. All the ceramics were single‐phase ferroelectrics with high Curie points (∼900°C). The doped ceramics, Ca 0.9 Na 0.1 Bi 2 Nb 2 O 9 , Ca 0.9 (NaLa) 0.1 Bi 2 Nb 2 O 9 , Ca 0.95 La 0.05 Bi 2 Nb 2 O 9 , and Ca 0.9 La 0.1 Bi 2 Nb 2 O 9 , had improved resistance to thermal depoling compared with Ca 2 Bi 2 Nb 2 O 9 and were stable up to 800°C. The donor dopants increased the dc electrical resistivity, while the acceptor dopants decreased it. The donor‐doped Ca 0.95 La 0.05 Bi 2 Nb 2 O 9 had a higher piezoelectric constant ( d 33 =12.8 pC/N) compared with CaBi 2 Nb 2 O 9 ( d 33 =5.8 pC/N), and its electrical resistivity was higher than 10 6 Ω·cm at 600°C. These properties suggest that doped CaBi 2 Nb 2 O 9 ceramics might be good candidates for high‐temperature piezoelectric applications.