Lead-free piezoceramics with giant strain in the system Bi{sub 0.5}Na{sub 0.5}TiO{sub 3}-BaTiO{sub 3}-K{sub 0.5}Na{sub 0.5}NbO{sub 3}. I. Structure and room temperature properties
- Institute of Materials Science, Technische Universitaet Darmstadt, Petersenstr. 23, 64287 Darmstadt (Germany)
Lead-free piezoelectric ceramics (1-x-y)Bi{sub 0.5}Na{sub 0.5}TiO{sub 3}-xBaTiO{sub 3}-yK{sub 0.5}Na{sub 0.5}NbO{sub 3} (0.05{<=}x{<=}0.07 and 0.01{<=}y{<=}0.03), have been synthesized by a conventional solid state sintering method. The room temperature ferroelectric and piezoelectric properties of these ceramics were studied. Based on the measured properties, the ceramics were categorized into two groups: group I compositions having dominant ferroelectric order and group II compositions displaying mixed ferroelectric and antiferroelectric properties at room temperature. A composition from group II near the boundary between these two groups exhibited a strain as large as {approx}0.45% at an electric field of 8 kV/mm. Polarization in this composition was not stable in that the piezoelectric coefficient d{sub 33} at zero electric field was only about 30 pm/V. The converse piezoelectric response becomes weaker when the composition deviated from the boundary between the groups toward either the ferroelectric or antiferroelectric compositions. These results were rationalized based on a field induced antiferroelectric-ferroelectric phase transition.
- OSTI ID:
- 21064540
- Journal Information:
- Journal of Applied Physics, Vol. 103, Issue 3; Other Information: DOI: 10.1063/1.2838472; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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