論文

査読有り
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
  • Susumu Takahashi
  • ,
  • Hirotaka Ogawa
  • ,
  • Akinori Kan

38
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.

リンク情報
DOI
https://doi.org/10.1016/j.jeurceramsoc.2017.08.022
ID情報
  • DOI : 10.1016/j.jeurceramsoc.2017.08.022
  • ISSN : 1873-619X
  • ISSN : 0955-2219
  • SCOPUS ID : 85029186899

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