Preparation of Preferentially Oriented Titanium Oxide Thin Films by Topotactic Structural Transformation Reaction

拓扑结构转化反应制备择优取向二氧化钛薄膜

基本信息

批准号：
13650894
负责人：
FACULTY Feng
金额：
$ 1.92万
依托单位：
Kagawa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650894/
关键词：
Topotatic structural transformation Soft chemical method Oriented thin film Barium titanate Titanium oxide Layered titanate Exfoliation of layered compound metal substrate ステンレス基板

项目摘要

In the preparations of preferentially oriented thin films, usually epitaxial crystal growth techniques are utilized. In this case, a single crystal substrate and lattice matching between the substrate crystal and the film crystal are necessary, meaning the high cost for the preparation of the epitaxial films. In the present study, we developed a novel process for the preparation of an oriented layered titanate thin film on stainless steel and Ti metal substrates by using an exfoliation-restacking technique, and preparation of oriented BaTiO_3 and TiO_2 thin films from the layered titanate film by using topotactic structural transformation reactions.In this process, a layered H^+-form titanate H_<1.07>Ti_<1.73>O_4・nH_2O (HTO) was used as precursor. HTO powder sample was exfoliated into the nano-sheets of elementary layer of its structure by reacting with an n-propylamine solution. The HTO thin film was prepared by dipping the substrates into the HTO nano-sheet solution and then drying in air at room temperature. The HTO nano-sheets restack on the surface of the substrate and form a preferentially oriented film of the layered titanate after drying. Oriented thin films of anatase and rutile types of TiO_2 were obtained after heat-treatment at 600 and 800℃ respectively. A BaTiO_3 film with a preferred orientation along [110] direction was obtained by hydrothermal treatment of the HTO film in a Ba(OH)_2 solution. The cubic BaTiO_3 film was obtained under low temperature conditions and tetragonal BaTiO_3 film under high temperature conditions. A capacitance measurement indicated that the BaTiO_3 film prepared by present method showed a much higher dielectric constant than that of BaTiO_3 films prepared by other methods. The method developed in this study will not be limited in the preparations of the titanium oxide films, but also useful for the preparation of other metal oxides oriented films.

在优选定向薄膜的制备中，通常使用外延晶体生长技术。在这种情况下，必须进行底物晶体和膜晶体之间的单晶底物和晶格匹配，这意味着制备外部膜膜的高成本。在演讲研究中，我们开发了一个新型的过程，用于制备在不锈钢和Ti金属底物上使用剥落式堆肥技术在不锈钢和Ti金属底物上制备，并制备定向的batio_3和Tio_2薄膜，从H_ <1.07> Ti_ <1.73> O_4 ・NH_2O（HTO）用作前体。通过与N-丙酰胺溶液反应，将HTO粉末样品剥落到其结构基本层的纳米片中。通过将基板浸入HTO纳米片溶液中，然后在室温下在空气中干燥来制备HTO薄膜。 HTO纳米片在基材表面重新扎根，并在干燥后形成层状钛酸盐的首选膜。在600和800°的热处理后，获得了剖析酶和金红石类型的定向薄膜。通过在BA（OH）_2溶液中对HTO膜的热液处理获得了沿[110]方向优选取向的BATIO_3膜。在高温条件下，在低温条件下获得了Cubic Batio_3膜在高温条件下获得。电容测量表明，通过当前方法制备的BATIO_3膜比其他方法制备的batio_3膜的固定常数要高得多。在这项研究中开发的方法将在氧化钛膜的制备过程中受到限制，而对于其他以金属氧化物为导向的膜的制备也有用。