Title :
Fabrication of lead-free piezoelectric (Na0.5K0.5)NbO3 ceramics by a modified solid-state reaction method
Author :
Fukada, Masaki ; Saito, Takehisa ; Kume, Hideki ; Wada, Takahiro
Author_Institution :
Dept. of Mater. Chem., Ryukoku Univ., Otsu
fDate :
5/1/2008 12:00:00 AM
Abstract :
Sodium potassium niobate, (Na0.5K0.5)NbO3, fine powder has been successfully synthesized at the low temperature of 550degC through a modified solid-state reaction method, in which urea [CO(NH2)2] plays an important role. High-density (Na0.5K0.5)NbO3 ceramics could be obtained by conventional sintering of the synthesized (Na0.5K0.5)NbO3 fine powder with the addition of 0.03 mol% Co3O4 as a sintering additive. The crystal structure, microstructure, and dielectric and piezoelectric properties were characterized. The (Na0.5K0.5)NbO3 ceramic showed a comparatively saturated P-E hysteresis loop. The (Na0.5K0.5)NbO3 ceramic also displayed piezoelectricity with a piezoelectric constant d33 of 126 pC/N and a planar electromechanical coupling factor kp of 33%.
Keywords :
crystal microstructure; crystal structure; density; dielectric hysteresis; piezoceramics; piezoelectricity; potassium compounds; sintering; sodium compounds; Na0.5K0.5NbO3; crystal structure; dielectric properties; high-density ceramics; lead-free piezoelectric ceramics; microstructure; modified solid-state reaction; piezoelectric constant; piezoelectric properties; piezoelectricity; planar electromechanical coupling factor; saturated P-E hysteresis loop; sintering additive; sodium potassium niobate; temperature 550 degC; Ceramics; Crystallization; Electric Impedance; Electrochemistry; Lead; Materials Testing; Phase Transition;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
DOI :
10.1109/TUFFC.2008.744
