2018年2月1日
Electronic states and cation distributions of MgAl2O4 and Mg0.4Al2.4O4 microwave dielectric ceramics
Journal of the European Ceramic Society
- ,
- ,
- 巻
- 38
- 号
- 2
- 開始ページ
- 593
- 終了ページ
- 598
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1016/j.jeurceramsoc.2017.08.022
- 出版者・発行元
- Elsevier Ltd
The electronic state and microwave dielectric properties of MgAl2O4 prepared using solid-state (MA-S) and molten salt (MA-M) methods and those of Mg0.4Al2.4O4 (M04A24) were investigated. The λ values, which correspond to the fraction of Al3+ cations in tetrahedral sites, for MA-S, MA-M, and M04A24 were 0.23, 0.41, and 0.60, respectively. In molecular orbital calculations, a larger overlap was observed between Al-3s or Al-3p in tetrahedral sites and O-2p orbitals for M04A24, and the bond order for Al[sbnd]O at tetrahedral sites of M04A24 (0.241) was higher than those for MA-S (0.178) and MA-M (0.205). The dielectric constant, εr, for M04A24 (7.6) was lower than those for MA-S and MA-M (both 7.9), and the highest quality factor, Q·f, was obtained for M04A24 (235, 800 GHz). It was found that the covalency of the Al[sbnd]O bonds in the MO4 tetrahedra is closely related to the Q・f values of the present ceramics.
- ID情報
-
- DOI : 10.1016/j.jeurceramsoc.2017.08.022
- ISSN : 1873-619X
- ISSN : 0955-2219
- SCOPUS ID : 85029186899