Zhou Zhen, Luo Jin, Sun Wei, Li Jing-Feng
State Key Laboratory of New Ceramics and Fine Processing, School of Materials, Science and Engineering, Tsinghua University, 100084 Beijing, P. R. China.
Phys Chem Chem Phys. 2017 Aug 2;19(30):19992-19997. doi: 10.1039/c7cp03530f.
Extensive studies on (BiNa)TiO-BaTiO piezoceramics have aroused growing interest in developing high-performance piezoelectric films based on this promising lead-free piezoelectric system. High quality (1 - x%) (BiNa)TiO-x% BaTiO (x = 0-15) thin films were synthesized on Pt(111)/Ti/SiO/Si(100) substrates via a sol-gel method. The phase transitions as functions of composition and temperature were investigated by X-ray diffraction (XRD) and temperature-dependent Raman spectra analysis. A morphotropic phase boundary (MPB) located at 5 ≤ x ≤ 10 was found in the films, being identical to that in bulk materials. Additionally, complicated structural changes with temperature in a wide composition range were observed, which correspond to the evolution from a low-symmetry ferroelectric phase or a relaxor phase to high-symmetry relaxor phases. The ferroelectricity and piezoelectricity were also systematically studied with an emphasis on the influence of composition and phase structure. A phase diagram focusing on the above two kinds of phase transitions has been proposed in this work.
对（BiNa）TiO-BaTiO压电陶瓷的广泛研究引发了人们对基于这种有前景的无铅压电体系开发高性能压电薄膜的日益浓厚的兴趣。通过溶胶-凝胶法在Pt(111)/Ti/SiO/Si(100)衬底上合成了高质量的（1 - x%）（BiNa）TiO-x% BaTiO（x = 0 - 15）薄膜。通过X射线衍射（XRD）和变温拉曼光谱分析研究了相变与成分和温度的关系。在薄膜中发现了位于5≤x≤10的准同型相界（MPB），这与体材料中的情况相同。此外，还观察到在很宽的成分范围内随温度发生的复杂结构变化，这对应于从低对称铁电相或弛豫相到高对称弛豫相的演变。还系统地研究了铁电性和压电性，重点关注成分和相结构的影响。在这项工作中提出了一个聚焦于上述两种相变的相图。
