DIELECTRIC AND PIEZOELECTRIC PROPERTIES OF LEAD-FREE Na_(0.5)Bi_(4.5-x)La_xTi_4O_(15) AND Na_(0.5)Bi_(4.5-x)Nd_xTi_4O_5 CERAMICS

摘要

The dielectric and piezoelectric properties of lead-free bismuth layered structure Na_(0.5)Bi_(4.5-x)La_xTi_4O_(15) (NBLT) AND Na_(0.5)Bi_(4.5-x)Nd_xTi_4O_5 (NBNT) ceramics are studied. The T_c and the epsilon_r of the NBLT and NBNT ceramics has been decreased and the shape of the dielectric constant curves has been broadened with increasing La and Nd concentration. The E_c of NBLT and NBNT ceramics diminished with increasing x, on the other hand, P_r reached the maximum value at NBLT-1.00 and NBNT-0.25 ceramics. In the NBLT ceramics, k_p increase with increasing La Concentration and Q_m exhibit the large values (2000 approx 3600) except the NBLT-1.00. In the NBNT ceramics, k_p remain nearly constant for all of the Nd concentrations, but Q_m get the maximum value of 3650 for NBNT-0.25.