| 研究実績の概要 |
The electric-field controlled topochemical reactions are explored in the past half year and our recent experimental results have demonstrate a successful interdisciplinary study between physics and chemistry. Our current achievements have already fulfilled the first question in our proposed research goals “Can we manipulate ions in vacancy rich layered reduced perovskite oxides using electric-field controlled ionic manipulation?” where an unexplored vacancy rich layered perovskite material, which cannot be obtained by physical or chemical method solely, have been successfully fabricated through the proposed interdisciplinary strategy.
To be more specific, when manipulating ions in the oxides, types of meta-stable phases were observed in our previous studies, which indicates that additional cations or anions could increase the total energy of the system greatly. Then these meta-stable phases with mixed-anions or protons could transform into other phases easily, because the increased in total energy also decreases the energy barrier for possible phase transitions. Thus, we eventually discovered a hidden structure which is unreported before. In general, this would enable us to develop a novel route of fabricating materials that can be hardly achieved at normal condition. Besides, such manipulation can also allow us to include more physics techniques (strain mediation, facet control, superlattice and etc.) with topochemical methods together, which eventually brings about a series of unexplored thin film materials.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
1: 当初の計画以上に進展している
理由
According to the proposed research plan, the first half year research should be focused on the thin film synthesizing and associated synchrotron X-ray experiments. So far we have focused on preparing highest quality perovskite films and performing interdisciplinary manipulation for the past half year. Samples for this study has been characterized extensively in our labs and we have already successfully achieved the epitaxial growth of high quality oxide thin films. Besides we have unexpectedly explored a new route to design oxide materials based on the combined technique between physics and chemistry, which was supposed to be explored in the second stage of the research plan. This indicates that our project goes very well along with the proposed plan.
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| 今後の研究の推進方策 |
First of all, we will continue explore the physical property of the newly discovered oxides, especially the synchrotron X-ray absorption (XAS) will be the most important part. The element specificity and valence state sensitivity of XAS make it a perfect tool for this purpose, in which the valence state, spin configuration as well as the oxygen stoichiometry can be clearly measured through the peak position as well as line shape in the x-ray absorption spectra. By comparing the experimental results with atomic multiplet theoretical calculations, we will first clarify the correlation of spin configuration (high-spin, low-spin or intermediate-spin) with the hydrogen concentrations. At the meantime, we will try to expand our strategy to various systems to verify the universality of this methods and this may bring about more opportunity to the undiscovered materials.
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