scholarly journals Biomimetic Synthesis of Zinc Oxide 3D Architectures with Gelatin as Matrix

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Yong Gan ◽  
Fubo Gu ◽  
Dongmei Han ◽  
Zhihua Wang ◽  
Guangsheng Guo
Keyword(s):  
Zinc Oxide ◽  
Absorption Spectrum ◽  
Absorption Band ◽  
Electrostatic Interaction ◽  
Biomimetic Synthesis ◽  
Broad Absorption ◽  
Broad Absorption Band ◽  
Structure And Property ◽  
Experimental Process ◽  
Ft Ir

Peanut-like and flower-like zinc oxide 3D architectures were synthesized via a facile biomimetic process using gelatin as matrix. Techniques of XRD, SEM, HRTEM, FT-IR, and UV-vis absorption spectra were used to characterize the structure and property of the zinc oxide architectures. The experimental results show that the peanut-like ZnO and flower-like ZnO architectures can be obtained through changing theZn2+concentration or the aging time. FT-IR spectra indicate that theZn2+is coupled with the C=O bond of the gelatin molecules through the electrostatic interaction. Based on the experimental process, the possible growth mechanism of the ZnO 3D architectures is proposed. UV-vis absorption spectrum of the peanut-like ZnO has a broad absorption band in the UV region, and the blue-shifting of the band is observed.

Study of Crystal Yb3+:Ca3Y2(BO3)4

2004 ◽  
Vol 19 (4) ◽  
pp. 1203-1207 ◽  
Author(s):  
Yan Wang ◽  
Chaoyang Tu ◽  
Changcang Huang ◽  
Zhenyu You
Keyword(s):  
Absorption Spectrum ◽  
Absorption Band ◽  
Emission Spectra ◽  
Czochralski Method ◽  
X Ray Diffraction ◽  
Broad Absorption ◽  
Broad Absorption Band ◽  
Orthorhombic System ◽  
X Ray ◽  
Broad Emission

Yb3+-doped single-crystal Ca3Y2(BO3)4 with dimension φ20 × 55 mm was grown by the Czochralski method. The structure of it was determined by x-ray diffraction. It belongs to the orthorhombic system, space group Pnma, with the following parameters: a= 7.1690(4), b = 15.4758(8), c = 8.5587(6) Å, V = 949.55(10)Å3, Mr = 537.51, Z = 2, Dc = 3.8 g/cm3, (MoKa) = 0.71073 Å, F(000) = 508, μ = 6.927 mm-1, final R = 0.0670, and wR = 0.1542 for 2975 independent reflections. The structure of Yb:Ca3Y2(BO3)4 is made up of three set of M-oxygen distorted polyhedrons, and three set of BO3 planar triangles. Ca2+ and Y3+ ions occupy three M sites statistically. Yb3+ ions substitute Y3+ ions to enter these three lattices. The adsorption and emission spectra were measured. It exhibits a broad absorption band ranging from 850 to 1000 nm in the absorption spectrum, which is well matched with the emission wavelength of a laser diode. A broad emission spectrum ranging from 927.95 to 1102.7 nm was observed under the excitation of 895 nm.

Hydrogen Quasi-Chemically Trapped between Defective Graphene Layers in Nanostructured Graphite

2007 ◽  
Vol 561-565 ◽  
pp. 1585-1588
Author(s):  
Yumiko Miyabe ◽  
Tomoko Yoshida ◽  
Shunsuke Muto ◽  
Tetsu Kiyobayashi
Keyword(s):  
Absorption Band ◽  
Hydrogen Atmosphere ◽  
Broad Absorption ◽  
Low Frequencies ◽  
Broad Absorption Band ◽  
Hydrogen Incorporation ◽  
Graphene Layers ◽  
Ft Ir ◽  
Alloys And Compounds ◽  
Electron Energy Loss

Direct evidences of hydrogen loosely trapped between graphene layers in nanostructured graphite prepared by mechanical milling in a hydrogen atmosphere are presented, based on a combinational study of FT-IR, electron diffraction (ED) and electron energy-loss spectroscopy (EELS). The FT-IR spectrum of nanostructured graphite exhibited a new broad absorption band at very low frequencies around 660 cm-1, which almost disappeared by annealing up to 800 K. ED and plasmon peaks in EELS detected the unusual shrinkage and subsequent expansion of the fragmented graphene interlayer distance by hydrogen incorporation and desorption with annealing, well correlated with the change in intensity of the 660 cm-1 IR band. All the present results support our previous studies [S. Muto et al., Jpn. J. Appl. Phys. 44, 2061 (2005); T. Kimura et al, J. Alloys and Compounds 413, 150 (2006).].

Accuracy of measurements of the band maximum shift for a broad absorption band

1973 ◽  
Vol 19 (5) ◽  
pp. 1538-1538
Author(s):  
A. I. Sidorova ◽  
T. V. Sukhanova ◽  
E. M. Ushakova
Keyword(s):  
Absorption Band ◽  
Broad Absorption ◽  
Broad Absorption Band ◽  
Band Maximum ◽  
Accuracy Of Measurements

Broad absorption band solar selective absorber analyzed by admittance loci

2016 ◽  
Author(s):  
Wei-Bo Liao ◽  
Ya-Chen Chang ◽  
Cheng-Chung Lee ◽  
Yu-Sheng Chen ◽  
Chien-Cheng Kuo
Keyword(s):  
Absorption Band ◽  
Broad Absorption ◽  
Broad Absorption Band ◽  
Admittance Loci

Optical and Scintillation Properties of Eu-Doped Calcium Orthoborate

2012 ◽  
Vol 508 ◽  
pp. 235-239 ◽  
Author(s):  
Yutaka Fujimoto ◽  
Yoshisuke Futami ◽  
Takayuki Yanagida ◽  
Shunsuke Kurosawa ◽  
N. Kawaguchi ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Absorption Band ◽  
Radio Frequency ◽  
Single Crystals ◽  
Heating System ◽  
Radio Frequency Heating ◽  
Broad Absorption ◽  
Broad Absorption Band ◽  
Decay Times ◽  
Frequency Heating

Single Crystals of Eu-Doped Calcium Orthoborate Have Been Grown by Micro-Pulling (μ-PD) Technique with Radio Frequency Heating System, and its Transmittance, Photoluminescence and Radiation Responses Were Investigated. In Transmittance Spectra, Eu-Doped Crystal Showed Broad Absorption Band around 200-450 nm, which Is due to the Complex of Charge Transfer (CT) Transition and 4f-4f Transition of Eu3+. Intense Eu2+5f-4f and Eu3+4f-4f Emission Peaks Were Observed when Excited to 265 nm and 385 nm, and the Calculated Decay Times Were 230 ns and 1.5 ms, Respectively.241Am 5.5 Mev α-Ray Excited Radioluminescence Spectra Indicated both Eu2+5f-4f and EuSuperscript text3+ 4f-4f Emission Peaks.

The Symmetry of the EL2 Defect in GaAs

1989 ◽  
Vol 163 ◽  
Author(s):  
P. Trautman ◽  
J.M. Baranowski
Keyword(s):  
Absorption Band ◽  
Point Group ◽  
Uniaxial Stress ◽  
Linear Dichroism ◽  
Broad Absorption ◽  
Broad Absorption Band ◽  
Zero Phonon Line ◽  
Localized State ◽  
Jahn Teller ◽  
Order Of Magnitude

AbstractLinear dichroism has been measured in the broad absorption band of the EL2 defect in GaAs under uniaxial stress. In addition, the splittings of the EL2 zero phonon line (ZPL) at 8378 cm-1 under uniaxial stress applied along [100], [111], and [110] directions have been measured. Splitting of the ZPL under [100] stress is over one order of magnitude smaller than under [111] stress, on the other hand, the linear dichroism in the broad absorption band is roughly equal for these two directions of stress. This is an evidence for the quenching of the coupling to tetragonal strains due to interaction with trigonal modes of the lattice (the Ham effect). Therefore, it is established, that the excited T2 state of EL2 is a localized state subject to dynamical Jahn-Teller coupling to trigonal modes of the lattice. The possibility that the excited T2 state has hydrogenic nature associated with the L minima is ruled out by the present results. The observed splittings of the ZPL together with polarization selection rules clearly indicate the tetrahedral Td symmetry of the EL2 defect ruling out any other point group in particular trigonal C3v In view of the presented experimental results, their interpretation, and recent theoretical investigations, the isolated arsenic antisite AsGa most successfully accounts for the properties of the neutral charge state of the EL2 defect.

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