Vertically Well-aligned (Ga1-xMnx)N Diluted Magnetic Semiconductor Nanowires with Above Room Temperature Ferromagnetic Transition
H. C. Jeon1, S. J. Lee1, T. W. Kang1, T. W. Kim2,Woo-Jin Lee3 and Kee Joo Chang3
1Quantum-functional SemiconductorResearchCenter, DonggukUniversity, 3-26, Pil-dong, Chung-ku, Seoul 100-715, Korea
2Advanced Semiconductor Research Center, Division of Electronics and Computer Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791, Korea
3Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea
Diluted magnetic semiconductor (DMS) quantum structures utilizing both ferromagnetic and semiconductor nanostructures have been attractive because of interest in investigations of fundamental physics and their potential applications in spintronic devices [1]. Among the various kinds of DMS materials with a room temperature Tc, (Ga1-xMnx)N DMSs have become particularly interesting because they are theoretically expected to have high values for Tc. Among many DMS structures, (III1-xMnx)V ferromagnetic semiconductor quantum structures have been particularly attractive due to their potential applications in spintronic devices and they have combined properties of both III-V semiconductors and Mn ferromagnetic compounds, and the excellent advantages derived by utilizing mature III-V based hetero-structure technology [2]. Recently, some works on the formation of (Ga1-xMnx)N nanowires have been reported, but systematic studies concerning the origin of the ferromagnetism mechanisms of (Ga1-xMnx)N DMS nanowires withoutcatalystgrown on Al2O3 (0001) substrates have not yet been performed. Furthermore, the origin of the ferromagnetism mechanisms of (Ga1-xMnx)N DMS nanowires is significantly important for understanding the electrical, magnetic, and optical properties of the nanowires.This paper reports data regarding the formationof (Ga1-xMnx)N DMS nanowires grown on Al2O3 (0001) substrates by using molecular beam epitaxy (MBE).
Vertically well-aligned (Ga1-xMnx)N nanowires withoutcatalyst were grown on Al2O3 (0001) substrates by using MBE. High-resolution TEM images showed that (Ga1-xMnx)N nanowires without defects and stacking faults had uniform morphologies with c-axis-oriented single crystalline wurzite structures. The magnetization curve as a function of the magnetic field at 5 K for the (Ga1-xMnx)N nanowires indicates ferromagnetism of the (Ga1-xMnx)N nanowires. And ferromagnetic properties of the (Ga1-xMnx)N nanowires are maintained above room temperature.These results can help improve understanding of the origin of the ferromagnetism mechanisms of (Ga1-xMnx)N diluted magnetic semiconductor nanowires.
Acknowledgements
This work was supported by the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government(MEST) (No. R17-2008-024-01000-0).
[1] S. Sapra, D. D. Sarma, S. Sanvito, and N. A. Hill, Nano Lett.2, 605-608 (2002).
[2] T. Dietl, H. Ohno, F. Matsukura, J. Cibert, D. Ferrand, Science287, 1019-1022(2000)