TAILIEUCHUNG - Nanowires_2

This volume is intended to orient the reader in the fast developing field of semiconductor nanowires, by providing a series of self-contained monographs focusing on various nanowire-related topics. Each monograph serves as a short review of previous results in the literature and description of methods used in the field, as well as a summary of the authors recent achievements on the subject. | 11 Low Temperature Phase Separation in Nanowires Sheng Yun Wu Department of Physics National Dong Hwa University Taiwan R. O. C. 1. Introduction The ways to develop one-dimensional 1D nanostructures such as nanowires nanorods nanobelts and nanotubes are being studied intensively due to their unique applications in mesoscopic physics and nanoscale electronic devices 1-3 . Structural phase transition between the wurtzite WZ and zinc-blend ZB GaN induced by the deposition conditions 4 temperature-mediated phase selection during the growth of GaN 5 and substrate control 6 by the crystallographic alignment of GaN have all been observed. It is known that x-ray scattering technique plays an important role in investigating the lattice excitations and structural transformation associated with thermal strain in 1D nanowires 7 . For example Dahara and co-workers 8 reported a phase transformation from hexagonal to cubic in Ga implaned GaN nanowires GaNWs . The SC16 phase of GaAs appears at high pressure can be transformed to the hexagonal WZ phase by reducing the pressure to the ambient one. WZ GaAs is stable in resisting a transformation to the ZB phase at temperatures up to 473 K at ambient pressure 9 . Currently most of the studies on the crystalline structure of GaNWs are focused on the stable hexagonal a-GaN and metal-stable cubic P-GaN. In this work we study the crystalline structure of GaNWs by using in situ low-temperature x-ray diffraction and Rietveld analysis 10 . Our findings show that the ZB phase starts to develop below 260 K. A finite size model wherein the random phase distribution is utilized to describe the development of short range atomic ordering. The phase separation was found to be reversible upon temperature cycling and occurred through the exchange and interaction of the characteristic size of the ordered domain of the GaN nanowires. 2. Important In situ low temperature x-ray diffraction was employed to investigate the phase separation of GaN .

• Hoá dầu
• Beam Epitaxy
• Material System
• Thermal Oxidation
• Reaction Technique
• Optoelectronic Applications
• Charge Injection
• Lecture ECE 6450 Microelectronic
• ECE 6450 Microelectronic
• Thin film deposition
• Metal organic CVD
• Molecular beam epitaxy)
• VNU Journal of Science
• Optical properties of Sb doped Ge films deposited
• Sb doped Ge films deposited on silicon substrate
• Molecular beam epitaxy
• The main stream CMOS technology
• Tạp chí khoa học
• GaN film
• Atomic force microscopy
• Root mean square
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