Publication Date:
2015-09-25
Description:
The electric-field-driven phase transition in (K, Na, Li)(Nb, Ta, Sb)O 3 lead-free piezoelectric ceramics was investigated by X-ray diffraction, Raman spectra, and the temperature dependences of permittivity spectra. After poling under different electric fields, phase of the ceramics transformed gradually from orthorhombic–tetragonal coexisting phase to orthorhombic phase, indicating that the crystal structure of ceramics was strongly sensitive to electric field as an external stimulus. A secondary phase K 3 Li 2 Nb 5 O 15 induced by electric field was detected in the ceramics with Li content of 7 mol%, which was close to the solubility limit of lithium. This field-induced secondary phase resulted from the movement of Li ions and the structural deformation induced by electric field. Moreover, piezoelectric constant d 33 increased with the increasing poling field strength and the enhancement can be attributed to the field-triggered domain switching. This study implied that in addition to temperature and composition, which has been reported in previous researches, electric field might be an effective way for inducing phase transition in lead-free piezoelectric ceramics and improving the electrical performances simultaneously.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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