Development of Room-temperature Ferromagnetic Nitride Semiconductors
| Project/Area Number |
14350169
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Electronic materials/Electric materials
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| Research Institution | Osaka City University |
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Principal Investigator |
NAKAYAMA Hiroshi Osaka City University, The Graduate School of Engineering, 教授 (30164370)
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| Co-Investigator(Kenkyū-buntansha) |
KULATOV Ertin General Physics Institute, Moscow Russia, 一般物理学研究所, international cooperative researcher
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥15,000,000 (Direct Cost: ¥15,000,000)
Fiscal Year 2003: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2002: ¥11,900,000 (Direct Cost: ¥11,900,000)
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| Keywords | GaN / Mn4N / Ferromagentic Semiconductors / MBE / Spin-diode / negative mayneto-resistance / (Ga, Mn)N / 室温強磁性 / (Ga, Mn)N / グラニュラー磁性半導体 / フェリ磁性 |
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| Research Abstract |
Mn_4N is perovskite-derived structure described as the chemical form of ABX_3 with A=Mn(I) at the corner positions, B=N at the body center and X=Mn(II) at the face centers of the cubic cell. The magnetic moments of Mn(I) and Mn(II) cant and the net magnetic moment is not cancelled. The ferrimagnetic transition temperature is around 500C. Our first-principles band-structure calculation of the Mn_4N shows that the Mn d states are metallic and well hybridize with p states of N. The up and down spin states coexist at, the Fermi level. On the other hand, the band-structure calculation of (Ga, Mn)N showed that the Mn d states are well localized and show the half metallic states giving the perfect spin-polarized electronic states at the Fermi level.
In this work, we have succeeded in the MBE growth of the ferrimagnetic Mn_4N and the heterostructure with (Ga, Mn)N. In the MBE work, we used NH_3 as N source instead of N_2-radical cell with RF-plasma excitation. The serious NH_3 adsorption on the
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internal wall of MBE chamber was avoided by heating up the whole chamber at about 150C by baking heater. Hence, the MBE method is called here "hot-wall MBE". Then, NH_3 pressure was stably set around 1.0×10^<-2> Pa during the growth. Firstly, Mn_4N/GaN/Al_2O_3(0001) and Mn_4N/(Ga, Mn)N/Al_2O_3(0001) heterostructures have been grown. The X-ray diffraction analysis showed that the polycrystalline Mn_4N layer was formed on the epitaxial GaN and (Ga, Mn)N. The hysteresis curves of the magneto-optical Kerr rotation were observed at room temperature. The saturated Kerr-rotation angles were around 0.01 degree at the magnetic field of 0.5T parallel to the growth planes for both structures. Mn_4N/GaN/(Ga, Mn)N tunneling magneto-resistance (TMR) structure has been also grown on ITO-coated quartz substrates. The nonlinear current-voltage characteristic has been observed as due to the TMR structure. An anisotropy in the magneto-resistance depending on the current direction through the TMR structure has been observed under the magnetic field perpendicular to the Mn_4N/GaN/(Ga, Mn)N growth plane at 70K. This suggests the spin-dependent carrier rectification through the Mn_4N/GaN/(Ga, Mn)N TMR structure. Less
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Report
(3 results)
Research Products
(34 results)
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[Presentation] Stability of Magnetic Phases in Zn_<1-x>M_xTe and Zn_<1-x>M_xO(M=V, Cr, Mn, Fe, Co)Studied by First-Principles and Optical Properties of Zn_<0.75>Cr_<0.25>Te2003
Author(s)
E.Kulatov, H.Nakayama, H.Ohta, K.Mochizuki, Yu.Uspenskii, H.Mariette
Organizer
International Conference on Magnetism(ICM)2003
Place of Presentation
Rome, Italy
Description
「研究成果報告書概要(和文)」より
Related Report
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[Presentation] Stability of Magnetic Phases in Zn_<1-x>M_xTe and Zn_<1-x>M_xO(M=V, Cr, Mn, Fe, Co)Studied by First-Principles and Optical Properties of Zn_<0.75>Cr_<0.25> Te2003
Author(s)
E.Kulatov, H.Nakayama, H.Ohta, K.Mochizuki, Yu.Uspenskii, H.Mariette
Organizer
International Conference on Magnetism(ICM)
Place of Presentation
Rome, Italy
Description
「研究成果報告書概要(欧文)」より
Related Report
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