Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 4615-4621 |
| Number of pages | 7 |
| Journal | Journal of Physics Condensed Matter |
| Volume | 18 |
| Issue number | 19 |
| DOIs | |
| Publication status | Published - 2006 May 17 |
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ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials
Cite this
Coexistence of Mn2+ and Mn3+ in ferromagnetic GaMnN. / Sonoda, S.; Tanaka, I.; Ikeno, H.; Yamamoto, Tomoyuki; Oba, F.; Araki, T.; Yamamoto, Y.; Suga, K.; Nanishi, Y.; Akasaka, Y.; Kindo, K.; Hori, H.
In: Journal of Physics Condensed Matter, Vol. 18, No. 19, 17.05.2006, p. 4615-4621.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Coexistence of Mn2+ and Mn3+ in ferromagnetic GaMnN
AU - Sonoda, S.
AU - Tanaka, I.
AU - Ikeno, H.
AU - Yamamoto, Tomoyuki
AU - Oba, F.
AU - Araki, T.
AU - Yamamoto, Y.
AU - Suga, K.
AU - Nanishi, Y.
AU - Akasaka, Y.
AU - Kindo, K.
AU - Hori, H.
PY - 2006/5/17
Y1 - 2006/5/17
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=33646393523&partnerID=8YFLogxK
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U2 - 10.1088/0953-8984/18/19/015
DO - 10.1088/0953-8984/18/19/015
M3 - Article
AN - SCOPUS:33646393523
VL - 18
SP - 4615
EP - 4621
JO - Journal of Physics Condensed Matter
JF - Journal of Physics Condensed Matter
SN - 0953-8984
IS - 19
ER -