Morphology Control of BiFeO3 Aggregates via Hydrothermal Synthesis
Morphology Control of BiFeO3 Aggregates via Hydrothermal Synthesis
复制标题
水热合成 BiFeO3 聚集体的形貌控制
DOI：
10.1107/s1600576715023845
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Takahashi M.,
中科院分区：
文献类型：
--
作者：
Suzuki K.;Tokudome Y.;Tsuda H.;Takahashi M.,
通常需要将具有特定形状衍生性质的结晶结构单元组装成聚集体，以拓宽其实际应用，因为结构单元的性质由于其取向而可以完全整合并用于聚集体中。在此，形貌控制的BiFeO3聚集体组成的定向结晶的建筑单元，通过水热过程中没有任何添加剂，和过饱和条件对聚集状态的影响进行了研究。过饱和条件，通过改变KOH浓度控制，被发现影响结晶建筑单元的形状。对于较低的过饱和度条件下，聚集体的形态被发现是密切相关的基本建筑单元的形状，结果表明，定向附着发生在特定的晶面之间的建筑单元。在高过饱和度条件下，聚集体的形态不能反映结构单元的形状，得到单分散的球形聚集体。随着过饱和度的增加，团聚体内部的微观结构由均匀致密变为稀疏核密壳结构。通过微观结构分析讨论了这些形态控制聚集体的形成机制。本发明的方法来控制使用的建筑单元的形状和聚集动力学的聚集体的形态也可以适用于其他微晶聚集系统，除了BiFeO3。
The assembly of crystalline building units with specific shape-derived properties into aggregates is often required to broaden their practical applications because the properties of the building units can be fully integrated and used in the aggregates owing to their orientation. Herein, morphology-controlled BiFeO3 aggregates composed of oriented crystalline building units were fabricated via a hydrothermal process without any additives, and the effects of the supersaturation conditions on the aggregation state were investigated. The supersaturation condition, controlled by varying the KOH concentration, was found to affect the shape of the crystalline building units. For lower supersaturation conditions, the morphology of the aggregates was found to be closely related to the shape of the fundamental building units, and the results indicated that oriented attachment occurred between specific crystal faces of the building units. Under a high supersaturation condition, the morphology of the aggregate did not reflect the shape of the building units and a monodispersed spherical aggregate was obtained. Further, the internal microstructures of the aggregates changed from homogeneous and dense to sparse core and dense shell structures with an increasing supersaturation condition. The formation mechanism of these morphology-controlled aggregates is discussed using microstructure analyses. The present approach to control the morphology of aggregates using the shape of the building units and aggregation kinetics could also be applicable for other microcrystalline aggregated systems in addition to BiFeO3.