Fabrication and characterization of (Pb(Mg_(1/3)Nb_(2/3))O_3, Pb(Yb_(1/2)Nb_(1/2))O_3, PbTiO_3) ternary system ceramics

摘要

New ternary compositions in the Pb(Mg_(1/3)Nb_(2/3))O_3-Pb(Yb_(1/2)Nb_(1/2))O_3-PbTiO_3 (PMN-PYbN-PT) system were prepared using 0.5Pb(Yb_(1/2)Nb_(1/2)) O_3-0.5PbTiO_3 (PYbNT) and (1-x)Pb(Mg_(1/3)Nb_(2/3))O_3-xPbTiO_3 (x = 0.26;;PMNT26 or x = 0.325;;PMNT32.5) powders synthesized via the columbite method. Dense (>= 96% of theoretical density) ceramics with PMN/PYbN mole ratios of 25/75 (R-25), 50/50 (R-50) and 75/25 (R-75T and R-75R) were fabricated by reactive sintering at 1000 °C for 4 h. Therefore, incorporation of PYbNT to PMNT successfully decreased sintering temperature of PMNT from 1200 °C-1250 °Cto 1000 °C. Samples with higher density and perovskite ratio together with lower weight loss possessed higher dielectric and piezoelectric values in each composition. The R-75 samples had remanent polarization (P_r) values of 34-36 μC/cm~2 and piezoelectric charge coefficient (d_(33)) of 560 pC/N. The sharp phase transition PMNT as a function of temperature became broader or more diffuse with increasing PYbNT content. However, PYbNT addition to PMNT increased Curie temperature (T_c) from 183 °C (for PMNT32.5) to 220-242 °C (for R-75T and R-75R) to 336 °C (for R-25). Therefore, these ternary compositions can be tailored for various high temperature applications due to the relatively higher T_c with enhanced piezoelectric and dielectric properties as compared to PMNT.