Complex morphotropic domain structure and ferroelectric properties in high-T-C single crystals of a ternary perovskite solid solution
Complex morphotropic domain structure and ferroelectric properties in high-T-C single crystals of a ternary perovskite solid solution
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三元钙钛矿固溶体高T-C单晶的复杂同向域结构和铁电性能
DOI：
10.1039/c8tc01198b
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发表时间：
2018
影响因子：
6.4
通讯作者：
Ye Zuo-Guang
中科院分区：
文献类型：
--
作者：
Luo Zeng;Zhang Nan;Liu Zenghui;Zhuang Jian;Zhao Jinyan;Ren Wei;Ye Zuo-Guang
具有高居里温度的铁电和压电材料由于其在极端条件下的应用需求而引起了越来越多的关注。在这项工作中，新的高TC铁电单晶（0.95-x）BiScO 3 -0.05Pb（Cd 1/3 Nb 2/3）O3-xPbTiO 3（BS-PCN-xPT）三元固溶体的各种成分已成功地生长。随着PT浓度的增加，观察到从菱面体相，通过准同型相界（MPB），到四方相的组合物诱导的结构交叉。在MPB区发现单斜相（空间群Pm）。介电常数的温度依赖性揭示了363-452 °C的高居里温度（在1 MHz下）。通过偏光显微镜（PLM）和压电响应力显微镜（PFM）系统表征的宏观和介观铁弹/铁电畴结构揭示了MPB组分晶体中单斜畴的存在。在单斜晶体中，剩余极化（33.2 μC cm−2）比菱面体相弱。所有研究的组合物都显示出高矫顽场（约EC = 40 kV cm-1）。高TC和稳定极化状态的存在表明BS-PCN-xPT单晶是应用的有希望的候选者，例如可以在广泛的条件下操作的机电换能器。
Ferroelectric and piezoelectric materials with a high Curie temperature (TC) have attracted increasing interest due to their requirement in applications under extreme conditions. In this work, novel high-TC ferroelectric single crystals of (0.95 − x)BiScO3–0.05Pb(Cd1/3Nb2/3)O3–xPbTiO3 (BS–PCN–xPT) ternary solid solution with various compositions have been successfully grown. With increasing PT concentration, a composition-induced structural crossover from a rhombohedral phase, through a morphotropic phase boundary (MPB), to a tetragonal phase, is observed. A monoclinic phase (space group Pm) is found at the MPB region. The temperature dependences of the dielectric permittivity reveal high Curie-temperatures of 363–452 °C (at 1 MHz). The macroscopic and mesoscopic ferroelastic/ferroelectric domain structures systemically characterized by polarized light microscopy (PLM) and piezoresponse force microscopy (PFM) reveal the existence of monoclinic domains in the crystals with the MPB composition. In the monoclinic crystals, the remnant polarization (33.2 μC cm−2) is weaker than that in the rhombohedral phase. All compositions studied show a high coercive field (around EC = 40 kV cm−1). The presence of a high TC and a stable poled state signifies that the BS–PCN–xPT single crystals are promising candidates for applications such as electromechanical transducers that can be operated in a wide range of conditions.