1999 Fiscal Year Annual Research Report

高温で磁気転換する半導体の創製

Research Project

Project/Area Number	11750003
Research Institution	Tohoku University
Principal Investigator	松倉文ひろ東北大学, 電気通信研究所, 助手 (50261574)
Keywords	(Ga,Mn)As / (Ga,Mn)Sb / 強磁性半導体 / k・p摂動法 / 正孔誘起強磁性 / 超格子構造 / 分子線エピタキシ
Research Abstract	本年度は、高温磁気相転移をする材料創製の指針をたてるために、磁化を加味したk・p法によるバンド計算を行い、平均場近似により磁性半導体の強磁性転移温度を初めて見積もった。この手法により現在実験的に得られている(Ga,Mn)Asの最高の磁気転移温度T_c=110Kを再現することを示し、よりT_cを上げるために必要な材料への知見を得ることに成功した。また(Ga,Mn)AsにおいてもMn組成と正孔濃度を上げることによりT_cを向上できる可能性があることを示した。実験的には正孔濃度を向上させるために、(Ga,Mn)As量子井戸中に(Al,Ga,Mn)As障壁層から正孔が供給されるような(Ga,Mn)As/(Al,Ga,Mn)As超格子構造を分子線エピタキシ法により作製しその特性を見積もったが、大幅なT_cの向上には至っていない。また、新しい材料として(Ga,Mn)Sbの作製を試みた。閃亜鉛構造のGaSbに固溶するMn濃度を結晶成長温度を下げることにより増加できることを実験的に示した。通常の結晶成長温度でGaSbに固溶するMn濃度は1%にも満たないが、それよりも300℃程度低い250℃の結晶成長ではパーセント・オーダのMnをGaSb結晶中に導入可能であることを明らかにした。

Research Products
(26 results)

All Other

All Publications (26 results)

[Publications] T.Dietl: "Zener Model Description of Ferromagnetism in Zinc-Blende Magnetic Semiconductors"Science. 287. 1019-1022 (2000)
[Publications] Y.Ohno: "Electrical spin injection in a ferromagnetic semiconductor heterostructures"Nature. 402. 790-792 (1999)
[Publications] Y.Ohno: "Spin relaxation in GaAs (110) quantum wells"Physical Review Letters. 83. 4196-4199 (1999)
[Publications] F.Matsukura: "Magnetotransport properties of (Ga,Mn)As/(Al,Ga)As/(Ga,Mn)As trilayer structures"Jounal of Magnetic Society of Japan. 23. 99-101 (1999)
[Publications] Ryota Terauchi: "Carrier mobility dependence of electron spin relaxation in GaAs quantum wells"Japanese Journal of Applied Physics. 74・10. 1409-1411 (1999)
[Publications] H.Ohno: "Spin-dependent tunneling and properties of ferromagnetic (Ga,Mn)As(invited)"Journal of Applied Physics. 85・8. 4277-4282 (1999)
[Publications] J.Szczytko: "Antiferromagnetic p-d exchange in ferromagnetic Ga_<1-x>Mn_xAs epilayers"Physical Review B. 59・20. 12935-12939 (1999)
[Publications] Y.Iye: "Metal-insulator transition and magnetotransport in III-V compound diluted magnetic semiconductors"Materials Science and Engineering B. 63. 88-95 (1999)
[Publications] A.Shen: "Low-temperature molecular beam epitaxial growth of GaAs and (Ga,Mn)As"Journal of Crystal Growth. 201/202. 679-683 (1999)
[Publications] S.P.Guo: "InAs and (In,Mn)As nanostructures grown on GaAs(110), (211)B and (311)B substrates"Journal of Crystal Growth. 201/202. 684-688 (1999)
[Publications] A.Sato: "X-ray diffraction study of InAs/AlSb interface bonds grown by molecular beam epitaxy"Journal of Crystal Growth. 201/202. 861-863 (1999)
[Publications] A.Sawada: "Interlayer coherence in v=1 and v=2 bilayer quantum Hall states"Physical Review B. 59・23. 14888-14891 (1999)
[Publications] F.Matsukura: "Properties of (Ga,Mn)As and their dependence on molecular beam growth conditions"Inst.Phys/Conf.Ser.. 162. 547-552 (1999)
[Publications] J.G.E Harris: "Integrated michromechanical cantilever magnetometory of Ga_<1-x>Mn_xAs"Applied Physics Letters. 75・8. 1140-1142 (1999)
[Publications] B.Beshoten: "Magnetic Circular Dochorism Studies of Carrier-Induces Ferromagnetism in (Ga_<1-x>Mn_x)As"Physical Review Letters. 83・15. 3073-3076 (1999)
[Publications] S.P.Guo: "Surfactant effect of Mn on the formation of self-organized InAs nonostructures"Journal of Crystal Growth. 208. 799-803 (2000)
[Publications] Y.Ohno: "Electron Spin Relaxation Beyond D'yakonov-Perel' Interaction in GaAs/AlGaAs Quantum Wells"Physica E. (in press). (2000)
[Publications] T.Dietl: "Ferromagnetism induced by free carriers in p-type structures of diluted magnetic semiconductors"Physica E. (in press). (2000)
[Publications] T.Omiya: "Magnetotransport properties of (Ga,Mn)As inverstigated at low temperature and high magnetic field"Physica E. (in press). (2000)
[Publications] T.Adachi: "Mobility dependence of electron spin relaxation tume in n-type InGaAs/InAlAs multiple quantum wells"Physica E. (in press). (2000)
[Publications] E.Abe: "Molecular Beam Epitaxy of III-V Diluted Magnetic Semiconductor (Ga,Mn)Sb"Physica E. (in press). (2000)
[Publications] Y.Ohno: "MBE growth oh hybrid ferromagnetic/non-magnetic semiconductor ; pn junctions based on (Ga,Mn)As"Applied Surface Science. (in press). (2000)
[Publications] F.Matsukura: "Molecular beam epitaxy of GaSb with high concentration of Mn"Applied Surface Science. (in press). (2000)
[Publications] F.Matsukura: "Magnetotransport properties of (Ga,Mn)Sb"Journal of Applied Physics. (in press). (2000)
[Publications] N.Akiba: "Spin-dependent transport in semiconducting ferromagnetic (Ga,Mn)As trilayer structures"Journal of Applied Physics. (in press). (2000)
[Publications] H.Ohldag: "Magnetic moment of Mn in the ferromagnetic semiconductor (Ga_<0.98>Mn_<0.02>)As"Applied Physics Letters. (in press). (2000)

1999 Fiscal Year Annual Research Report

高温で磁気転換する半導体の創製

Principal Investigator

松倉 文ひろ 東北大学, 電気通信研究所, 助手 (50261574)

Research Products

[Publications] T.Dietl: "Zener Model Description of Ferromagnetism in Zinc-Blende Magnetic Semiconductors"Science. 287. 1019-1022 (2000)

[Publications] Y.Ohno: "Electrical spin injection in a ferromagnetic semiconductor heterostructures"Nature. 402. 790-792 (1999)

[Publications] Y.Ohno: "Spin relaxation in GaAs (110) quantum wells"Physical Review Letters. 83. 4196-4199 (1999)

[Publications] F.Matsukura: "Magnetotransport properties of (Ga,Mn)As/(Al,Ga)As/(Ga,Mn)As trilayer structures"Jounal of Magnetic Society of Japan. 23. 99-101 (1999)

[Publications] Ryota Terauchi: "Carrier mobility dependence of electron spin relaxation in GaAs quantum wells"Japanese Journal of Applied Physics. 74・10. 1409-1411 (1999)

[Publications] H.Ohno: "Spin-dependent tunneling and properties of ferromagnetic (Ga,Mn)As(invited)"Journal of Applied Physics. 85・8. 4277-4282 (1999)

[Publications] J.Szczytko: "Antiferromagnetic p-d exchange in ferromagnetic Ga_<1-x>Mn_xAs epilayers"Physical Review B. 59・20. 12935-12939 (1999)

[Publications] Y.Iye: "Metal-insulator transition and magnetotransport in III-V compound diluted magnetic semiconductors"Materials Science and Engineering B. 63. 88-95 (1999)

[Publications] A.Shen: "Low-temperature molecular beam epitaxial growth of GaAs and (Ga,Mn)As"Journal of Crystal Growth. 201/202. 679-683 (1999)

[Publications] S.P.Guo: "InAs and (In,Mn)As nanostructures grown on GaAs(110), (211)B and (311)B substrates"Journal of Crystal Growth. 201/202. 684-688 (1999)

[Publications] A.Sato: "X-ray diffraction study of InAs/AlSb interface bonds grown by molecular beam epitaxy"Journal of Crystal Growth. 201/202. 861-863 (1999)

[Publications] A.Sawada: "Interlayer coherence in v=1 and v=2 bilayer quantum Hall states"Physical Review B. 59・23. 14888-14891 (1999)

[Publications] F.Matsukura: "Properties of (Ga,Mn)As and their dependence on molecular beam growth conditions"Inst.Phys/Conf.Ser.. 162. 547-552 (1999)

[Publications] J.G.E Harris: "Integrated michromechanical cantilever magnetometory of Ga_<1-x>Mn_xAs"Applied Physics Letters. 75・8. 1140-1142 (1999)

[Publications] B.Beshoten: "Magnetic Circular Dochorism Studies of Carrier-Induces Ferromagnetism in (Ga_<1-x>Mn_x)As"Physical Review Letters. 83・15. 3073-3076 (1999)

[Publications] S.P.Guo: "Surfactant effect of Mn on the formation of self-organized InAs nonostructures"Journal of Crystal Growth. 208. 799-803 (2000)

[Publications] Y.Ohno: "Electron Spin Relaxation Beyond D'yakonov-Perel' Interaction in GaAs/AlGaAs Quantum Wells"Physica E. (in press). (2000)

[Publications] T.Dietl: "Ferromagnetism induced by free carriers in p-type structures of diluted magnetic semiconductors"Physica E. (in press). (2000)

[Publications] T.Omiya: "Magnetotransport properties of (Ga,Mn)As inverstigated at low temperature and high magnetic field"Physica E. (in press). (2000)

[Publications] T.Adachi: "Mobility dependence of electron spin relaxation tume in n-type InGaAs/InAlAs multiple quantum wells"Physica E. (in press). (2000)

[Publications] E.Abe: "Molecular Beam Epitaxy of III-V Diluted Magnetic Semiconductor (Ga,Mn)Sb"Physica E. (in press). (2000)

[Publications] Y.Ohno: "MBE growth oh hybrid ferromagnetic/non-magnetic semiconductor ; pn junctions based on (Ga,Mn)As"Applied Surface Science. (in press). (2000)

[Publications] F.Matsukura: "Molecular beam epitaxy of GaSb with high concentration of Mn"Applied Surface Science. (in press). (2000)

[Publications] F.Matsukura: "Magnetotransport properties of (Ga,Mn)Sb"Journal of Applied Physics. (in press). (2000)

[Publications] N.Akiba: "Spin-dependent transport in semiconducting ferromagnetic (Ga,Mn)As trilayer structures"Journal of Applied Physics. (in press). (2000)

[Publications] H.Ohldag: "Magnetic moment of Mn in the ferromagnetic semiconductor (Ga_<0.98>Mn_<0.02>)As"Applied Physics Letters. (in press). (2000)

松倉文ひろ東北大学, 電気通信研究所, 助手 (50261574)