Coexistence of Mn2+ and Mn3+ in ferromagnetic GaMnN

S. Sonoda, I. Tanaka, H. Ikeno, T. Yamamoto, F. Oba, T. Araki, Y. Yamamoto, K. Suga, Y. Nanishi, Y. Akasaka, K. Kindo, H. Hori

研究成果: Article査読

43 被引用数 (Scopus)


Considerable efforts have been devoted recently to synthesizing diluted magnetic semiconductors having ferromagnetic properties at room temperature because of their technological impacts for spintronic devices. In 2001 successful growth of GaMnN films showing room temperature ferromagnetism and p-type conductivity was reported. The estimated Curie temperature was 940 K at 5.7% of Mn, which is the highest among diluted magnetic semiconductors ever reported. However, the electronic mechanism behind the ferromagnetic behaviour has still been controversial. Here we show experimental evidence using ferromagnetic samples that Mn atoms are substitutionally dissolved into the GaN lattice and they exhibit mixed valences of +2 (majority) and +3. The p-type carrier density decreases significantly at very low temperatures. At the same time, magnetization dramatically decreases. The results imply that the ferromagnetic coupling between Mn atoms is mediated by holes in the mid-gap Mn band.

ジャーナルJournal of Physics Condensed Matter
出版ステータスPublished - 2006 5 17

ASJC Scopus subject areas

  • 材料科学(全般)
  • 凝縮系物理学


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