Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10653252 | Solid State Communications | 2005 | 5 Pages |
Abstract
(Bi0.5Na0.5)0.94Ba0.06TixO1+2x lead-free piezoceramics with x varying from 0.97 to 1.03 were fabricated and characterized in order to investigate the effects of TiO2-nonstoichiometry on the piezoelectric properties and depolarization temperature of (Bi0.5Na0.5)0.94Ba0.06TiO3 composition. X-ray diffraction (XRD) analysis showed that all samples have a single phase of perovskite structure with rhombohedral symmetry. Piezoelectric and dielectric measurements revealed that deficiency of TiO2 leads to an increase in the piezoelectric coefficient (d33), free relative permittivity (ε33T/ε0), and loss tangent (tan δ) besides an increase in the electromechanical coupling coefficient (kp) within a certain amount, while excess of TiO2 results in a decrease in kp, d33, and ε33T/ε0, but an increase in tan δ. Depolarization temperature (Td) measurement indicated a decrease and an increase in Td as a result of increasing TiO2 deficiency and TiO2 excess, respectively. This TiO2-nonstoichiometry also induced changes in the remanent polarization (Pr) and coercive field (Ec) of the ceramics.
Keywords
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Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
X.X. Wang, S.W. Or, X.G. Tang, H.L.W. Chan, P.K. Choy, P.C.K. Liu,