图 书 馆
SrTiO3颗粒的合成：形状、尺寸和晶体生长方向的调整Synthesis of SrTiO3 particles: tailoring the shape, size and crystal growth orientation |
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| 课程网址: | http://videolectures.net/ipssc2017_contala_synthesis/ |
| 主讲教师: | Alja Čontala |
| 开课单位: | 约瑟夫·斯特凡研究所 |
| 开课时间: | 2017-05-23 |
| 课程语种: | 英语 |
| 中文简介: |  |
| 课程简介: | Control of the size, shape and crystal growth orientation of multifunctional materials is of high interest, because these characteristics influence the material’s electrical, magnetic and optical properties. SrTiO3 particles were identified as good photo catalyst. SrTiO3 particles could be also used as a substrate for epitaxial growth of other perovskites. In recent years, a number of synthesis techniques have been developed to fabricate SrTiO3 crystals (e.g. molten salt synthesis, hydrothermal synthesis, sol−gel method, coprecipitation) [1]. SrTiO3, is widely known ABO3-type perovskite. Synthesis of anisotropically shaped SrTiO3 particles is still a great challenge, because these particles tend to grow in cube- or sphere-like rather than in anisotropic shape due to the high symmetry of their crystal structure. Different approaches to control the shape and size of ABO3 – type perovskites were reported [2], including topochemical conversion [3], [4]. Desired template for the preparation of anisotropic SrTiO3 particles should exhibit anisotropic shape and possesses perovskite units with corner-sharing [TiO6] 8- octahedra. For our study the plate shape and cubic crystal structure are preferable. More possibilities on the selection of the template exists, however we decided to use Bi4Ti3O12 platelets as template particles since it can be easily synthesized in the shape of plate by molten salt method. In this research the topochemical conversion was performed under hydrothermal conditions. To the best of our knowledge, the hydrothermal growth of SrTiO3 on the Bi4Ti3O12 plates and their complete conversion in to SrTiO3 has not been reported yet. Reaction parameters (e.g. temperature, time, reactant concentration, NaOH concentration and Sr/Ti ratio) were studied and different morphology of SrTiO3 particles was observed. Different mechanism pathways based on the selection of reaction parameters will be discussed. |
| 关 键 词: | 多功能材料; 合成技术; 拓扑化学转化 |
| 课程来源: | 视频讲座网 |
| 数据采集: | 2021-11-05：zkj |
| 最后编审: | 2021-11-05：zkj |
| 阅读次数: | 62 |