Effect Of Sintering Aid On Sintering Temperature And Electrical Properties Of (Ba 0.85 Ca 0.15 )(Zr 0.1 Ti 0.9 )O 3 Ceramic Materials

Piezoelectric ceramics materials have excellent performance in many application areas, such as electronic communications, precise instruments, national defense constructions, and also in our daily life like electronic musical cards. Those common implements are relevant with piezoelectric ceramics which attracted significant attentions. In 2009, Ba(Zr_0.2Ti_0.8)O₃-(Ba_0.7Ca_0.3)Ti₀₃ lead-free piezoelectric ceramics was firstly reported by the team of Ren Xiaobing in Xi'an Jiaotong University. The piezoelectric performance is outstanding at morphotropic phase boundary ?MPB?, the value of d₃₃ is as high as 620 pC/N. (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃ ceramics become a promising substitute for PZT piezoelectric ceramics. However, sintering temperature of (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃ ceramics is high and its temperature stability is low, which seriously affect the application. In this article, by doping the oxide like Li₂O, CuO and glass phase CuO-B2O₃-SiO₂, the sintering temperature of ceramic was reduced, and electrical properties were improved as well as the stability of electric properties, which made it a good candidate for further industrial application. The main results are as follows:1. (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃-x Li₂O lead-free piezoelectric ceramics were designed and prepared by traditional solid phase sintering method. The effect of sintering temperature and doping amount of the ceramics on phase structure, microstructure and electric properties were discussed. The results show that sintering temperature dropped from 1440 ? to 1340 ?, about 100?, when the doping amount of Li₂O is 0.02.At this point, the ceramic exhibited the admirable electrical properties, which are shown as followed:d₃₃=378pC/N, k_p=0.45, P_r=7.0?C/cm2, E_c=1.57kV/cm, Tc= 78.92?,?r=5193, tan?=0.029. From impedance spectrum diagram of (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃-x Li₂O ceramic, we can see that the ceramic gradually turned electrical heterogeneous structure into electrical homogeneous structure doping Li₂O. At the temperature range of 30-70 ?, the stability of electrical properties is favorable.2. (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃-xCuO lead-free piezoelectric ceramics were made by the traditional solid phase sintering method. The effects on phase structure, microstructure and electric properties of different sintering temperature and doping amount of the ceramics were discussed. The results indicate that sintering temperature dropped from 1440 ? to 1260 ?, about 180?, when the doping amount of CuO is 0.010. At this moment, the ceramic exhibited the admirable electrical properties, which are shown as followed:d₃₃=463pC/N,k_p=0.49, P_r=7.93?C/cm2,E_c=1.22kV/cm, Tc= 78.1?, ?r=4283, tan?=0.021. From impedance spectrum diagram of (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃-xCuO ceramic, we find that the ceramic gradually turned electrical heterogeneous structure into electrical homogeneous structure doping CuO. From 30 ? to 70 ?, the stability of electrical properties is favorable.3. (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃-xwt.%?CuO-B2O₃-SiO₂? lead-free piezoelectric ceramics were designed and prepared by traditional solid phase sintering method. The effects of sintering temperature and doping amount of the ceramics on phase structure, microstructure and electric properties were studied. The results exhibit that sintering temperature dropped from 1440 ? to 1270 ?, about 180?, when the doping amount of CuO-B2O₃-SiO₂ is 0.3. At this moment, the ceramic exhibited the admirable electrical properties, which are shown as followed:d₃₃=521pC/N,k_p=0.46, P_r=8.61?C/cm2, E_c=1.49kV/cm,Tc=88.79 ?,?r=3112, tan?=0.039. From 30 ? to 80 ?, the stability of electrical properties is favorable.