Christensen Mads, Einarsrud Mari-Ann, Grande Tor
Department of Materials Science and Engineering, NTNU Norwegian University of Science and Technology, Trondheim NO-7491, Norway.
Materials (Basel). 2017 Feb 22;10(2):213. doi: 10.3390/ma10020213.
Piezoelectric ceramics are widely used in actuator applications, and currently the vast majority of these devices are based on Pb ( Zr , Ti ) O 3 , which constitutes environmental and health hazards due to the toxicity of lead. One of the most promising lead-free material systems for actuators is based on Bi 0 . 5 Na 0 . 5 TiO 3 (BNT), and here we report on successful fabrication of BNT thin films by aqueous chemical solution deposition. The precursor solution used in the synthesis is based on bismuth citrate stabilized by ethanolamine, NaOH , and a Ti-citrate prepared from titanium tetraisopropoxide and citric acid. BNT thin films were deposited on SrTiO 3 and platinized silicon substrates by spin-coating, and the films were pyrolized and annealed by rapid thermal processing. The BNT perovskite phase formed after calcination at 500 °C in air. The deposited thin films were single phase according to X-ray diffraction, and the microstructures of the films shown by electron microscopy were homogeneous and dense. Decomposition of the gel was thoroughly investigated, and the conditions resulting in phase pure materials were identified. This new aqueous deposition route is low cost, robust, and suitable for development of BNT based thin film for actuator applications.
压电陶瓷广泛应用于致动器领域，目前绝大多数此类器件都基于Pb(Zr,Ti)O3，由于铅的毒性，该材料对环境和健康构成危害。用于致动器的最有前景的无铅材料体系之一是基于Bi0.5Na0.5TiO3（BNT），在此我们报告通过水基化学溶液沉积成功制备BNT薄膜。合成中使用的前驱体溶液基于由乙醇胺、NaOH稳定的柠檬酸铋以及由四异丙醇钛和柠檬酸制备的柠檬酸钛。通过旋涂将BNT薄膜沉积在SrTiO3和镀铂硅衬底上，然后通过快速热处理对薄膜进行热解和退火。在空气中500°C煅烧后形成BNT钙钛矿相。根据X射线衍射，沉积的薄膜为单相，电子显微镜显示的薄膜微观结构均匀且致密。对凝胶的分解进行了深入研究，并确定了得到纯相材料的条件。这种新的水相沉积路线成本低、稳定性好，适用于开发用于致动器应用的基于BNT的薄膜。
