碱式碳酸钴掺杂量对BCZT无铅压电陶瓷性能和结构的影响

摘要

采用传统固相法制备了碱式碳酸钴掺杂不同量的Ba0.85Ca0.15Ti0.9Zr0.1O3(简称BCZT)系列无铅压电陶瓷,借助扫描电镜(SEM)和X射线衍射仪(XRD)等研究了不同碱式碳酸钴掺杂量(x=0,0.55,0.89,1.3,1.8 wt.％)对BCZT无铅压电陶瓷的物相组成、显微结构及压电性能和介电性能的影响.结果表明:碱式碳酸钴的加入并没有改变所制备陶瓷的相结构,仍为单一斜方相钙钛矿,当x=1.8wt.％时,出现杂相.随着碱式碳酸钴掺杂量(x)的增大,BCZT无铅压电陶瓷的压电系数(d33)、平面机电耦合系数(kp)先增大后减小,介质损耗(tan δ)先减小后增大,而相对介电常数(εr)一直增大.当碱式碳酸钴(x)为1.3wt.％时,BCZT无铅压电陶瓷的综合性能最佳:d33=135 pC/N,εr=3399,kp=0.38,tanδ =0.029.%Ba0.85Ca0.15Ti0.9Zr0.1O3(abbreviated as BCZT) lead-free piezoelectric ceramics doped with different amounts of basic cobalt carbonate were prepared by a traditional solid state method. The effects of basic cobalt carbonate doping amounts (x=0, 0.55, 0.89,1.3,1.8 wt.%) on the phase composition, microstructure, piezoelectric properties and dielectric properties of the as-prepared BCZT ceramics were studied by scanning electron microscope (SEM), X-ray diffraction (XRD) and other analyzing instruments. The results show that when the doping amount (x) is less than 1.3 wt.%, the B-site substitution of Co3+ does not change the crystal structure and all the ceramics possess single-phase perovskite structure with orthorhombic symmetry. When the doping amount (x) is 1.8 wt.%, impurity phases appear. With the increase of the doping amount, the piezoelectric constant (d33) and planar electron mechanical coupling coefficient (kp) of all the samples increase firstly and decrease subsequently, the dielectric loss (tanδ) decreases firstly and then increases, while the relative permittivity (ε1) increases all the time. When the doping amount is 1.3 wt.%, the BCZT ceramics possess optimal properties: d33=135 pC/N, tan6 = 0.029, kp = 0.38, and εr=3399.