无容器相变技术制备BaTi2O5纳米非晶球及纳米陶瓷
文献类型：学位论文
| 作者 | 巴国庆 |
| 学位类别 | 硕士 |
| 答辩日期 | 2012-05-19 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 李建强 |
| 关键词 | 无容器相变 非晶晶化 高折射玻璃 介电性 |
| 其他题名 | Fabrication of Amorphous BaTi2O5 Nano-spheres and Nanocrystalline Ceramics by Containerless Method |
| 学位专业 | 化学工程 |
| 中文摘要 | BaTi2O5是BaO-TiO2体系富Ti区中一类重要的功能材料，当前对BaTi2O5的研究主要集中在铁电性和非晶体光学等性能方面，而对BaTi2O5纳米陶瓷介电性能与晶体结构关系以及纳米级BaTi2O5非晶球的研究还没有涉及。本论文利用非晶晶化法制备出BaTi2O5纳米陶瓷。XRD研究了其不同退火工艺下的纳米陶瓷物相结构组成；SEM研究了其不同退火工艺条件下结晶形貌、晶粒度等；并研究了其介电性能与晶体形状之间的关系。结果表明：一定晶粒度范围内， BaTi2O5纳米陶瓷室温下的介电常数高于常规技术制备的BaTi2O5，而介电损耗则小于常规技术制备的BaTi2O5，在此粒径范围之外，介电常数和介电损耗均小于常规技术制备的BaTi2O5，这是由于纳米尺寸效应造成的。论文采用无容器相变技术，以微米级BaTi2O5和La4(Zr1.35-x,Ti7.65+x)O24为原料粉，成功制备出纳米尺度的BaTi2O5 和La4(Zr1.35-x,Ti7.65+x)O24非晶球，利用射频等离子束流成功制备出纳米尺度的非晶球，这是首次利用射频等离子体制备出钛酸盐系纳米尺度的LNF玻璃球。纳米尺度的BaTi2O5非晶球具有良好的光学性能：具有很宽的光学透过范围(250 nm～11 μm)；由于不存在氧缺陷而没有出现在紫外光下光致发光的现象；FT-IR结果显示波长在6.6 μm后，样品的多声子进程吸收开始增加，在红外范围内截止的波长超过了11 μm；纳米尺度的BaTi2O5非晶球作为减反膜用在太阳能电池板上，在整个紫外-可见-近红外的光谱范围内平均可以增加30%的光学吸收率。 |
| 英文摘要 | BaTi2O5 is one of the most important compounds in the Ti-rich compounds of BaO-TiO2 system. As a new lead-free material, it is a very promising material for its properties in dielectric and optical application. Nanocrystlline BaTi2O5 is fabricated by Crystallization Method. The phases of the nanocrystalline BaTi2O5 were characterized by using an X-ray diffraction, and their morphologies were investigated by a field-emission scanning electron microscope. The dependence of structural knowledge on the dielectric properties of nanocrystalline BaTi2O5 glass-ceramic is explored. The results shows that, at the certain grain size the dielectric constant of the nanocrystalline BaTi2O5 is higher than that of those which were fabricated by conventional method, but the loss is smaller. These interesting phenomena can be explained by the size effect. Nanometer-sized BaTi2O5 and La4(Zr1.35-x,Ti7.65+x)O24 spherical glasses without conventional network-forming oxides were fabricated by the containerless phase change process for the first time. The as-fabricated BaTi2O5 nanomaterials possess perfect spherical shape and superior optical properties. The nanosized BaTi2O5 spheres have a wide transmittance window at least from 250 nm to 11 μm; no absorption can be seen in the visible region due to certain defects such as oxygen vacancies. The multiphonon processes in the glass give rise to absorption at wavelengths above 6.6 μm. The cut-off wavelength at IR regions is over 11 μm. As the Antireflective coatings in the photovoltaic devices, reflectance decreased 30% at the vis-region. |
| 语种 | 中文 |
| 公开日期 | 2013-09-25 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1862]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 巴国庆. 无容器相变技术制备BaTi2O5纳米非晶球及纳米陶瓷[D]. 中国科学院研究生院. 2012. |
入库方式： OAI收割
来源：过程工程研究所
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