【Molecular Systems and Materials Chemistry】Transparent bulk amorphous alumina- High-pressure process achieved unusual densely packed amorphous structure composed of five-coordinated pyramids and six-coordinated octahedra, leading to a large dielectric constant exceeding that of crystals –
Program-specific professor Atsunobu Masuno, collaborated with a research team led by Associate professor Hideki Hashimoto of Kogakuin University, has succeeded in synthesizing millimeter-sized transparent amorphous bulk samples of alumina, a single-component oxide thought to be incapable of forming glass, using a high-pressure process at room temperature. The transparent bulk samples exhibited high thermal conductivity and hardness, and demonstrated a dielectric constant of approximately 11.3, exceeding that of the representative crystalline phase, α-Al2O3 (sapphire).
This research was published online on April 7, 2026, in the Journal of the American Chemical Society.
Paper Information
| Title | Bulk Amorphous Alumina: The Density-Driven Interplay of Pentahedral Pyramids and Octahedra for High Dielectric Permittivity |
| Authors | Hideki Hashimoto, Yohei Onodera, Rei Okuno, Masashi Miyakawa, Hitoshi Yusa, Takashi Taniguchi, Sho Kakizawa, Shuya Sato, Takao Shimizu, Taro Kuwano, Takato Abe, Naoki Takata, Dasom Kim, Koji Yazawa, Kenzo Deguchi, Shinobu Ohki, Koji Kimoto, Shunsuke Shimizu, Yuto Okawara, Yuta Nishina, Aiko Shimada, Ryuichi Maekawa, Koji Ohara, Yuta Shuseki, Hidetoshi Morita, Tomoko Sato, Hiroyo Segawa, Hiroki Taniguchi, Atsunobu Masuno, Takeharu Yoshii, Koji Kawada, Toshinori Okura, Shinji Kohara |
| Journal | Journal of the American Chemical Society |
| DOI | 10.1021/jacs.5c22344 |
| KURENAI |