Publication Date:
2014-04-11
Description:
Structure and piezoelectric coefficient ( d 33 ) of lead-free 7.5% mole BaTiO 3 -doped ( Bi 0.5 Na 0.5 ) TiO 3 (BNT-7.5%BT) polycrystalline piezoceramics have been characterized systematically as a function of poling electric ( E ) field. Dielectric permittivity and loss were also measured as functions of frequency and temperature. The piezoelectric coefficient d 33 after poling at E = 35 kV/cm can reach d 33 ~186 pC/N, which is the highest value reported among (1− x ) BNT– x BT compositions. A prior poling E field can reduce rhomobherdal lattice distortion, and enhance tetragonal phase and polarization ordering, that contribute significantly to the rapid raise of d 33 and lower depolarizing temperature (T d ). The reduced dielectric permittivity for the poled sample is attributed to ordered state and the pinning of field-induced nanodomain walls by the presence of oxygen vacancies.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Permalink