Effects of La-Doping on Phase Structure and Electrical Properties of Pb(Mg_(1/3)Nb_(2/3))_(0.67)Ti_(0.33)O_3 Ceramic

摘要

La-doped Pb(Mg_(1/3)Nb_(2/3))_(0.67)Ti_(0.33)O_3 ceramics were fabricated by a two-stage sintering method from conventional raw materials. The effects of La doping on the phase structure and electrical properties of ceramics were investigated. X-ray diffraction analysis showed that the pyrochlore phase increased with the increase of La-doping level. The effects of La doping on the dielectric, ferroelectric and piezoelectric properties of the ceramics were also investigated. The results showed that La doping seriously weakened the electrical properties of the ceramics. The ceramics possess optimum properties (d_(33) = 239pC/N, P_r = 10.6μC/cm～2, E_c = 8.5 kV/cm, tanδ = 0.029, ε_r = 2250) when the doping level is low (x = 0.02).