Ferromagnetism and electronic structures of nonstoichiometric Heusler-alloy Fe3-xMnxSi Epilayers grown on Ge(111).
For the study of ferromagnetic materials which are compatible with group-IV semiconductor spintronics, we demonstrate control of the ferromagnetic properties of Heusler-alloy Fe3-xMnxSi epitaxially grown on Ge(111) by tuning the Mn composition x. Interestingly, we obtain L2(1)-ordered structures even for nonstoichiometric atomic compositions. The Curie temperature of the epilayers with x approximately 0.6 exceeds 300 K. Theoretical calculations indicate that the electronic structures of the nonstoichiometric Fe3-xMnxSi alloys become half-metallic for 0.75 < or = x < or = 1.5. We discuss the possibility of room-temperature ferromagnetic Fe(3-x)Mn(x)Si/Ge epilayers with high spin polarization.
Hamaya
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Department of Electronics, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan. hamaya@ed.kyushu-u.ac.jp
Itoh
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H
Nakatsuka
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O
Ueda
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K
Yamamoto
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K
Itakura
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M
Taniyama
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T
Ono
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T
Miyao
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M