Dependence of crystal symmetry, electrical conduction property and electronic structure of LnFeO3 (Ln: La, Pr, Nd, Sm) on kinds of Ln3+

Eiki Niwa, Tsubasa Sato, Yuki Watanabe, Yuichiro Toyota, Yoshikiyo Hatakeyama, Ken Judai, Katsumi Shozugawa, Motoyuki Matsuo, Takuya Hashimoto

研究成果: Contribution to journalArticle査読

6 被引用数 (Scopus)

抄録

Dependence of crystal symmetry, electrical conductivity, chemical state of Fe and optical property of LnFeO3 (Ln: La, Pr, Nd, Sm) on kinds of Ln3+ was investigated. All the LnFeO3 showed orthorhombic structure, with which order of high crystal symmetry was LaFeO3 > PrFeO3 > NdFeO3 > SmFeO3. Using tolerance factor, the order was successfully explained. The electrical conductivity of all the specimens could be explained by using small polaron hopping model. With increasing crystallite symmetry, electrical conductivity increased and activation energy for hopping conduction decreased. This can be ascribed to larger overlapping of Fe3d orbital and O2p orbital on nearly linear Fe-O-Fe bond in LnFeO3 with higher crystal symmetry. The larger overlapping of Fe3d orbital and O2p orbital in LnFeO3 with higher crystal symmetry can also be an origin of larger spin-spin interaction detected by Mössbauer spectroscopy and larger optical band gap observed by diffuse reflectance spectroscopy. Since chemical state of Fe, evaluated by Mössbauer spectroscopy, in LnFeO3 is fundamentally constant at +3 regardless of kinds of Ln3+, carrier concentration of LnFeO3 was revealed to be constant. It is concluded that the predominant factor which determine the electrical property of LnFeO3 is mobility affected by crystal symmetry.

本文言語英語
ページ(範囲)501-506
ページ数6
ジャーナルJournal of the Ceramic Society of Japan
123
1438
DOI
出版ステータス出版済み - 6 1 2015
外部発表はい

All Science Journal Classification (ASJC) codes

  • セラミックおよび複合材料
  • 化学 (全般)
  • 凝縮系物理学
  • 材料化学

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