Local electronic structure of Cr in the II–VI diluted ferromagnetic semiconductor Zn<sub>1-<i>x</i></sub>Cr<sub><i>x</i></sub>Te
説明
The electronic structure of the Cr ions in the diluted ferromagnetic semiconductor Zn$_{1-x}$Cr$_x$Te ($x=0.03$ and 0.15) thin films has been investigated using x-ray magnetic circular dichroism (XMCD) and photoemission spectroscopy (PES). Magnetic-field ($H$) and temperature ($T$) dependences of the Cr $2p$ XMCD spectra well correspond to the magnetization measured by a SQUID magnetometer. The line shape of the Cr $2p$ XMCD spectra is independent of $H$, $T$, and $x$, indicating that the ferromagnetism is originated from the same electronic states of the Cr ion. Cluster-model analysis indicates that although there are two or more kinds of Cr ions in the Zn$_{1-x}$Cr$_x$Te samples, the ferromagnetic XMCD signal is originated from Cr ions substituted for the Zn site. The Cr 3d partial density of states extracted using Cr $2p \to 3d$ resonant PES shows a broad feature near the top of the valence band, suggesting strong $s$,$p$-$d$ hybridization. No density of states is detected at the Fermi level, consistent with their insulating behavior. Based on these findings, we conclude that double exchange mechanism cannot explain the ferromagnetism in Zn$_{1-x}$Cr$_{x}$Te.
Accepted for New Journal of Physics. Single column, 21 pages, 7 figures
収録刊行物
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- New Journal of Physics
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New Journal of Physics 10 (5), 055011-, 2008-05-23
IOP Publishing
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詳細情報 詳細情報について
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- CRID
- 1362544418747988224
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- ISSN
- 13672630
- http://id.crossref.org/issn/13672630
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- データソース種別
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- Crossref
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