Effects of pH on the crystal structure, morphology and microwave dielectric properties of Bi12TiO20 ceramics synthesized by citrate sol-gel method
Effects of pH on the crystal structure, morphology and microwave dielectric properties of Bi12TiO20 ceramics synthesized by citrate sol-gel method
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pH值对柠檬酸盐溶胶-凝胶法合成Bi12TiO20陶瓷晶体结构、形貌及微波介电性能的影响
DOI：
10.1007/s10854-015-2815-8
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发表时间：
2015
影响因子：
2.8
通讯作者：
Liu Shuya
中科院分区：
文献类型：
--
作者：
Zhang Yun;Zhang Yingchun;Fu Baojian;Hong Ming;Xiang Maoqiao;Liu Zhiang;Liu Hui;Liu Shuya
以柠檬酸为金属螯合剂，采用溶胶-凝胶法制备bi12tio20陶瓷。通过加入氢氧化铵（NH4OH）将初始前驱体的pH值从6调整到13。本文系统地研究了pH值对柠檬酸与金属离子形成螯合物的影响。研究了不同pH值下bi12tio20陶瓷的晶体结构、微观结构和微波介电性能。扫描电镜和能谱分析结果表明，在pH值为11的条件下，成功制备了相对密度超过理论密度96%的bi12tio20相。密度、离子极化率和微观结构的变化对bi12tio20陶瓷的微波介电性能有显著影响。在pH为11的情况下，750°C烧结的bi12tio20陶瓷表现出良好的微波介电性能：εr= 39.55,Q×f= 3950 GHz, τf= - 17 ppm/°C，表明它们是LTCC应用的有希望的介电候选材料。
Bi12TiO20ceramics were prepared via a modified sol–gel route using citric acid as a metal chelating agent. The pH value of the initial precursor was adjusted from 6 to 13 by the addition of ammonium hydroxide (NH4OH). The effects of pH value on the formation of chelate complex between citric acid and metal ions were systematically investigated in this work. Furthermore, the crystal structure, microstructure and microwave dielectric properties of Bi12TiO20ceramics derived at various pH values were characterized. Scanning electron microscopy and energy dispersive spectroscopy indicated that a single Bi12TiO20phase with high relative densities above 96 % of the theoretical density was successfully achieved at pH 11. The variations in density, ionic polarizability and microstructure had a remarkable effect on the microwave dielectric properties of Bi12TiO20ceramics. In the case of pH 11, Bi12TiO20ceramics sintered at 750 °C exhibited promising microwave dielectric properties:εr= 39.55,Q×f= 3950 GHz, andτf= − 17 ppm/°C, indicating that they were promising dielectric candidates for LTCC applications.