| Institution: | 1. Graduate School of Science and Technology for Innovation, Yamaguchi University, 1677-1, Yoshida, Yamaguchi, 7538512 Japan
Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima, 739-8526 Japan;2. Graduate School of Science and Technology for Innovation, Yamaguchi University, 1677-1, Yoshida, Yamaguchi, 7538512 Japan;3. Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima, 739-8526 Japan;4. Faculty of Environmental Earth Science, Hokkaido University, Sapporo, 060-0810 Japan;5. State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029 P. R. China;6. Research Institute for Electronic Science, Hokkaido University, Sapporo, 0010020 Japan;7. Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Sendai, 980-8577 Japan |
| Abstract: | The structural phase of a metal oxide changes with temperature and pressure. During phase transitions, component ions move in multidimensional metal–oxygen networks. Such macroscopic structural events are robust to changes in particle size, even at scales of around 10 nm, and size effects limiting these transitions are particularly important in, for example, high-density memory applications of ferroelectrics. In this study, we examined structural transitions of the molecular metal oxide Na@(SO3)2(n-BuPO3)4MoV4MoVI14O49]5? (Molecule 1 ) at approximately 2 nm by using single-crystal X-ray diffraction analysis. The Na+ encapsulated in the discrete metal-oxide anion exhibited a reversible order–disorder transition with distortion of the Mo–O molecular framework induced by temperature. Similar order–disorder transitions were also triggered by chemical pressure induced by removing crystalline solvent molecules in the single-crystal state or by substituting the countercation to change the molecular packing. |
