Self-assembly and crystallization Behavior of mesoporous, crystalline HfO2 thin films:: A model system for the generation of mesostructured transition-metal oxides
Self-assembly and crystallization Behavior of mesoporous, crystalline HfO2 thin films:: A model system for the generation of mesostructured transition-metal oxides
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DOI：
10.1002/smll.200500024
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发表时间：
2005-08-01
期刊：
影响因子：
13.3
通讯作者：
Sanchez, C
中科院分区：
文献类型：
--
作者：
Brezesinski, T;Smarsly, B;Sanchez, C
通过蒸发诱导自组装结合溶胶-凝胶工艺，然后通过合适的后热处理程序来引发结晶，制备了结晶氧化铪介孔薄膜。使用一种新型嵌段共聚物模板作为结构导向剂，它产生了扭曲的球形介孔立方体排列，其尺寸可以通过合适的技术进行量化，例如椭圆偏振孔隙率测定法、小角X射线散射和原子力显微镜。通过温度依赖的原位X射线散射实验，详细了解介观结构氧化铪的结晶过程的性质。这些研究表明，结晶发生，在限制的，介观结构，作为从脱水，无定形形式的氧化铪的固-固过渡。该研究表明，新型模板的一个主要优点是聚合物能够在高达400-450摄氏度的温度下稳定无定形氧化铪的介观结构。
Mesoporous thin films of crystalline hafnium oxide were fabricated by evaporation-induced self-assembly in combination with sol-gel processing, followed by a suitable post heat-treatment procedure to initiate the crystallization. A novel type of block-copolymer template was used as structure-directing agent, which generated a distorted cubic arrangement of spherical mesopores, the size of which could be quantified by suitable techniques, such as ellipsometry-porosimetry, small-angle X-ray scattering, and atomic force microscopy. Detailed insights into the nature of the crystallization process of mesostructured hafnium oxide were obtained by temperature-dependent, in situ X-ray scattering experiments. These investigations revealed that crystallization takes place, within the confinement of the, mesostructure, as a solid-solid transition from a dehydrated, amorphous form of hafnium oxide. The study suggests that one main benefit of the novel template results from the ability of the polymer to stabilize the mesostructure of amorphous hafnium oxide up to 400-450 degrees C.