Multi-disciplinary Materials Research Center and State Key Lab of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, 710049, China.
Phys Rev Lett. 2009 Dec 18;103(25):257602. doi: 10.1103/PhysRevLett.103.257602. Epub 2009 Dec 15.
We report a non-Pb piezoelectric ceramic system Ba(Ti(0.8)Zr(0.2))O(3)-(Ba(0.7)Ca(0.3))TiO(3) which shows a surprisingly high piezoelectric coefficient of d(33) approximately 620 pC/N at optimal composition. Its phase diagram shows a morphotropic phase boundary (MPB) starting from a tricritical triple point of a cubic paraelectric phase (C), ferroelectric rhombohedral (R), and tetragonal (T) phases. The high piezoelectricity of the MPB compositions stems from the composition proximity of the MPB to the tricritical triple point, which leads to a nearly vanishing polarization anisotropy and thus facilitates polarization rotation between 001T and 111R states. We predict that the single-crystal form of the MPB composition of the present system may reach a giant d(33) = 1500-2000 pC/N. Our work may provide a new recipe for designing highly piezoelectric materials (both Pb-free and Pb-containing) by searching MPBs starting from a TCP.
我们报道了一种非铅基压电陶瓷体系 Ba(Ti(0.8)Zr(0.2))O(3)-(Ba(0.7)Ca(0.3))TiO(3)，其在最佳组成时表现出高达 620 pC/N 的令人惊讶的压电系数 d(33)。其相图显示从立方顺电相 (C)、铁电三方相 (R)和四方相 (T)的三临界点出发存在一个准同型相界 (MPB)。MPB 组成的高压电性能源于 MPB 与三临界点的接近，这导致了极化各向异性几乎为零，从而有利于 001T 和 111R 状态之间的极化旋转。我们预测，本体系 MPB 组成的单晶形式可能达到 1500-2000 pC/N 的巨大 d(33)。我们的工作可能通过从 TCP 开始搜索 MPB，为设计高压电材料（无铅和含铅）提供了一种新方法。
