Piezoelectric characteristics of low temperature sintering Pb(Mn 1/3Nb 2/3)O 3–Pb(Ni 1/3Nb 2/3)O 3–Pb(Zr 0.50Ti 0.50)O 3 according to the addition of CuO and Fe 2O 3

Abstract

In this study, in order to develop the composition ceramics for low temperature sintering multilayer piezoelectric actuator and ultrasonic vibrator, Pb(Mn 1/3Nb 2/3)O 3–Pb(Ni 1/3Nb 2/3)O 3–Pb(Zr 0.50Ti 0.50)O 3 (abbreviated as PMN–PNN–PZT) ceramics were fabricated using Li 2CO 3 and Na 2CO 3 as sintering aids, their structural, piezoelectric and dielectric characteristics were investigated according to the addition of CuO and Fe 2O 3, respectively. The addition of CuO and Fe 2O 3 improved sinterability and density and suppressed secondary phase. In the CuO added PMN–PNN–PZT ceramics, mechanical quality factor ( Q m) was improved due to the acceptor doping effect. However, in the Fe 2O 3 added PMN–PNN–PZT ceramics, it seemed that Fe 2O 3 reacted as softner because dielectric constant ( ɛ r) and electromechanical coupling factor ( k p) were significantly increased by the increase of grain size and sinterability. At 0.2 wt.% CuO added specimen sintered at 900 °C, density, electromechanical coupling factor ( k p), mechanical quality factor ( Q m), dielectric constant ( ɛ r) and piezoelectric constant ( d 33) showed the optimum value of 7.856 g/cm 3, 0.60, 1130, 1018 and 346 ( pC/N), respectively. At 0.2 wt.% Fe 2O 3 added specimen sintered at 900 °C, density, electromechanical coupling factor ( k p), mechanical quality factor ( Q m), dielectric constant ( ɛ r) and piezoelectric constant ( d 33) showed the optimum value of 7.850 g/cm 3, 0.62, 975, 1275 and 377 ( pC/N), respectively. Taking into consideration above piezoelectric properties, it was concluded that PMN–PNN–PZT ceramics using 0.2 wt.% Fe 2O 3 as additive showed the piezoelectric characteristics suitable for low loss and low temperature sintering multilayer piezoelectric actuator application.