The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform

Jianlin Liu - One of the best experts on this subject based on the ideXlab platform.

  • smooth surface low Electron Concentration and high mobility zno films on c plane sapphire
    Journal of Crystal Growth, 2011
    Co-Authors: Sheng Chu, Muhammad M Morshed, Jian Huang, Jianlin Liu
    Abstract:

    Abstract ZnO thin films were grown on c -plane sapphire substrate using plasma-assisted molecular beam epitaxy. The thickness of MgO buffer layers was optimized for structural and electrical properties of the epi-ZnO films. It is found that with MgO buffer growth time of 60 s, the epi-ZnO film exhibited narrow X-ray diffraction peak as well as low surface roughness. In the meantime, the Electron Concentration reached a minimum of 2.03×10 16 /cm 3 and high mobility of 169.4 cm 2 /V S. These results demonstrate a route to grow good crystals together with excellent mobility and low residual Electron Concentration, which can ultimately satisfy the requirement for acceptor doping as well as device engineering.

  • Electron Concentration dependent magnetization and magnetic anisotropy in zno mn thin films
    Applied Physics Letters, 2008
    Co-Authors: Zheng Yang, Jianlin Liu, M Biasini, W P Beyermann
    Abstract:

    Well-above room temperature and Electron Concentration dependent ferromagnetism was observed in n-type ZnO:Mn films, indicating long-range ferromagnetic order. Magnetic anisotropy was also observed in these ZnO:Mn films, which is another indication for intrinsic ferromagnetism. The Electron-mediated ferromagnetism in n-type ZnO:Mn contradicts the existing theory that the magnetic exchange in ZnO:Mn materials is mediated by holes.

Gordon J. Miller - One of the best experts on this subject based on the ideXlab platform.

  • influence of valence Electron Concentration on laves phases structures and phase stability of pseudo binary mgzn2 xpdx
    ChemInform, 2015
    Co-Authors: Srinivasa Thimmaiah, Gordon J. Miller
    Abstract:

    The series of title compounds (0.15 ≤ x ≤ 1.0) is synthesized from the elements (Ta tubes, Ar, 750 °C, 18 h, followed by annealing at 400 °C for 5 d, 90—95% yields) and characterized by single crystal XRD and TB-LMTO-ASA Electronic structure calculations to analyze the effect of valence Electron Concentration on MgZn2.

  • phase transformation driven by valence Electron Concentration tuning interslab bond distances in gd5gaxge4 x
    Journal of the American Chemical Society, 2003
    Co-Authors: Yurij Mozharivskyj, Wonyoung Choe, And Alexandra O Pecharsky, Gordon J. Miller
    Abstract:

    X-ray single crystal and powder diffraction studies on the Gd(5)Ga(x)()Ge(4)(-)(x)() system with 0 < or = x < or = 2.2 reveal dependence of interslab T-T dimer distances and crystal structures themselves on valence Electron Concentration (T is a mixture of Ga and Ge atoms). While the Gd(5)Ga(x)()Ge(4)(-)(x)() phases with 0 < or = x < or = 0.6 and valence Electron Concentration of 30.4-31 e(-)/formula crystallize with the Sm(5)Ge(4)-type structure, in which all interslab T-T dimers are broken (distances exceeding 3.4 A), the phases with 1 < or = x < or = 2.2 and valence Electron Concentration of 28.8-30 e-/formula adopt the Pu(5)Rh(4)- or Gd(5)Si(4)-type structures with T-T dimers between the slabs. An orthorhombic Pu(5)Rh(4)-type structure, which is intermediate between the Gd(5)Si(4)- and Sm(5)Ge(4)-type structures, has been identified for the Gd(5)GaGe(3) composition. Tight-binding linear-muffin-tin-orbital calculations show that substitution of three-valent Ga by four-valent Ge leads to larger population of the antibonding states within the dimers and, thus, to dimer stretching and eventually to dimer cleavage.

Zikang Tang - One of the best experts on this subject based on the ideXlab platform.

  • zno film with ultra low background Electron Concentration grown by plasma assisted mbe using mg film as the buffer layer
    Materials Research Bulletin, 2012
    Co-Authors: Mingming Chen, Quanlin Zhang, Jiashi Cao, Yuan Zhu, Xuchun Gui, Chunlei Yang, Rong Xiang, Zikang Tang
    Abstract:

    High quality ZnO epilayer with background Electron Concentration as low as 2.6 1014 cm 3 was obtained by plasma-assisted MBE on c-sapphire using a thin Mg film as the buffer layer. High-resolution XRD measurement shows a sharp (0 0 2) peak with full width at half maximum (FWHM) of only 0.0298. Photoluminescence spectroscopy presents a weak defect-related near-edge emission. A metal– semiconductor–metal (MSM) typed photodetector based on the material demonstrates a response of 43 A/W under the bias of 1 V and an ON/OFF ratio of 104. This un-doped ZnO with ultra-low background Electron Concentration could be a promising starting material for p-type doping.

Christine A. Wang - One of the best experts on this subject based on the ideXlab platform.

  • Raman spectroscopic determination of Electron Concentration in n-type GaInAsSb
    Journal of Applied Physics, 2009
    Co-Authors: James E. Maslar, Wilbur S. Hurst, Christine A. Wang
    Abstract:

    Phonon-plasmon coupled mode Raman spectra of n-type GaInAsSb were measured at room temperature as a function of Electron Concentration. A relatively simple spectral model for the Electronic contribution to the dielectric function was evaluated to determine the Electron Concentration from the bulk coupled mode spectra. The Electron Concentration was determined from a Raman spectrum by minimizing the sum of the squared residuals between a measured and a simulated spectrum. The only two fitting parameters were the Fermi energy and a plasmon damping parameter. The Electron Concentrations determined from the fits to the Raman spectra were compared to the Electron Concentrations determined from single magnetic field Hall effect measurements that were corrected to account for carriers in two conduction band minima. Compared to the results obtained from the Hall effect measurements, the Electron Concentrations obtained using Raman spectroscopy were as much as ≈19% lower at low doping levels but not more than ≈1% ...

  • Spectroscopic determination of Electron Concentration in n-type GaSb
    Journal of Applied Physics, 2008
    Co-Authors: James E. Maslar, Wilbur S. Hurst, Christine A. Wang
    Abstract:

    Phonon-plasmon coupled mode Raman spectra of n-type GaSb were measured at room temperature as a function of Electron Concentration. These spectra were obtained using an optical system based on 752.55 nm excitation. Utilization of this wavelength permits greater sensitivity to GaSb coupled mode Raman scattering over a wider doping range than is possible with visible wavelength excitation-based systems. A relatively simple spectral model for the Electronic contribution to the dielectric function was evaluated for determination of Electron Concentration from the bulk coupled mode spectra. The Electron Concentrations were determined from the Raman spectra by minimizing the sum of the squared residuals between a measured and a simulated spectrum as a function of Fermi energy and a plasmon damping parameter. The Electron Concentrations determined from the fits to the Raman spectra were compared to the Electron Concentrations determined from single magnetic field Hall effect measurements that were corrected to a...

Andreas Wiesmann - One of the best experts on this subject based on the ideXlab platform.

  • Ionospheric Electron Concentration Effects on SAR and INSAR
    2006 IEEE International Symposium on Geoscience and Remote Sensing, 2006
    Co-Authors: Urs Wegmüller, Charles Werner, Tazio Strozzi, Andreas Wiesmann
    Abstract:

    The launch of ALOS and the high potential expected for the L-band PALSAR motivated us to investigate ionospheric Electron Concentration effects using JERS L-band SAR data acquired at high latitudes. An important focus of our work was on the identification of ionospheric effects and resulted in methodologies to detect ionospheric effects in single SAR acquisitions as well as in repeat-orbit pairs. For cases where significant ionospheric anomalies are present, procedures to improve SAR offset tracking and interferometric results are proposed and the retrieval of free Electron density maps is discussed.