Structure and electrical properties of (La,Ta)-doped (K 0.5 Na 0.5 ) 0.94 Li 0.06 Nb 0.95 Ta 0.05 O 3 ceramic

Piezoceramics (K 0.5 Na 0.5 ) 0.94−3x Li 0.06 La x Nb 0.95 Ta 0.05 O 3 (KNLNT-La x ) were synthesized by the conventional solid-state reaction process. The effects of (La,Ta)-doping on the phase structure and electrical properties of (KNLNT-La x ) ceramics were investigated. X-ray diffraction analysis showed that the crystal structure of the ceramics with high level of La-doping possessed pseudo-cubic phase and the pseudo-cubic phase structure of the ceramics seriously weakened the dielectric, ferroelectric and piezoelectric properties of the ceramics. In addition, it was found that the ceramics with (La,Ta)-doping displayed a relative lower loss tangent (tand) from room temperature to approximately 350°C.