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以固相法合成的BaTiO3粉体和La(NO3)3溶液为反应前驱物,NaOH为矿化剂,对BaTiO3粉体表面进行镧掺杂水热改性。利用X射线衍射仪、扫描电镜、Fourier红外光谱仪和透射电镜等研究了水热处理后BaTiO3粉体及陶瓷的相组成、晶粒尺寸、颗粒形貌及电性能。结果表明:对不同镧掺杂浓度的BaTiO3粉体进行水热处理后,粉体粒径变小,粒度分布范围变窄,颗粒形貌变得圆整,实现了高温、高压条件下的水热“整形”作用。在BaTiO3粉体颗粒表层形成了一层约50nm厚的富镧层,实现了高温高压下对BaTiO3陶瓷粉体的改性。将改性后的BaTiO3粉体制成陶瓷,其室温电阻率测试结果表明,经水热处理后的粉体改善了镧在钛酸钡陶瓷中的掺杂均匀性,掺杂半导化浓度范围加宽。
BaTiO3 powders and La (NO3) 3 synthesized by solid-state reaction were used as precursors and NaOH as mineralizer. The surface of BaTiO3 powder was hydrothermally modified by lanthanum. The phase composition, grain size, grain morphology and electrical properties of BaTiO3 powders and ceramics after hydrothermal treatment were investigated by X-ray diffraction, scanning electron microscopy, Fourier infrared spectroscopy and transmission electron microscopy. The results show that after hydrothermal treatment of BaTiO3 powders with different lanthanum doping concentrations, the particle size becomes smaller and the particle size distribution becomes narrower, and the particle morphology becomes rounded. The hydrothermal conditions under high temperature and high pressure are achieved. “Plastic” effect. In the BaTiO3 powder particles formed a layer of about 50nm thick lanthanum-rich layer, to achieve high temperature and high pressure BaTiO3 ceramic powder modification. The modified BaTiO3 powder made of ceramic, the room temperature resistivity test results show that the powder after hydrothermal treatment to improve lanthanum in BaTiO3 ceramic doping uniformity, doping semiconductor concentration range plus width.