The electronic structure and the photoluminescence property of the photocatalyst BaZn1/3Nb2/3O3

The photocatalyst BaZn1/3Nb2/3O3 with ABO3 perovskite structure has been synthesized by using a solid-state reaction process. It was characterized by x-ray diffraction and photoluminescence spectroscopy. The luminescence band centers around 285 nm and shows a large Stokes shift compared with the excitation spectrum, indicating a strong electron–phonon interaction in the photocatalyst BaZn1/3Nb2/3O3. The electronic structure of BaZn1/3Nb2/3O3 was calculated by using the pseudopotential method of the density function theory. It shows that the conduction band should be mainly composed of the Nb 4d states, and the valence band should be mainly composed of the O 2p state. The densities of the O 2p states and the Zn 4s states at the bottom of the conduction band are very low. The Zn 4s states show an expanded structure, which was proposed to be helpful for the migration of the photoexcited carriers, thus favoring the photocatalytic activity of BaZn1/3Nb2/3O3.

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Low-temperature lattice structure anomaly in theLaFeAsO0.93F0.07superconductor by x-ray absorption spectroscopy: Evidence for a strong electron-phonon interaction

Physical Review B ◽

10.1103/physrevb.78.214513 ◽

2008 ◽

Vol 78 (21) ◽

Cited By ~ 34

Author(s):

C. J. Zhang ◽

H. Oyanagi ◽

Z. H. Sun ◽

Y. Kamihara ◽

H. Hosono

Keyword(s):

Low Temperature ◽

Absorption Spectroscopy ◽

Lattice Structure ◽

Phonon Interaction ◽

Strong Electron ◽

X Ray ◽

Electron Phonon Interaction ◽

Temperature Lattice ◽

X Ray Absorption

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STRUCTURE AND TRANSPORT PROPERTIES OF Pr1-xSr1+xCoO4

Modern Physics Letters B ◽

10.1142/s0217984908017710 ◽

2008 ◽

Vol 22 (32) ◽

pp. 3195-3205 ◽

Cited By ~ 1

Author(s):

M. LI ◽

S. L. HUANG ◽

Z. M. LV ◽

J. L. ZHANG ◽

H. Y. WU ◽

...

Keyword(s):

Raman Scattering ◽

Low Frequency ◽

X Ray Diffraction ◽

Phonon Interaction ◽

Band Shift ◽

X Ray ◽

Electron Phonon Interaction ◽

Scattering Spectra ◽

Raman Scattering Spectra ◽

Dramatic Variation

Powder X-ray diffraction, Raman scattering and infrared spectra at different doping (x = 0 ~ 0.5) on polycrystalline Pr 1-x Sr 1+x CoO 4 were performed. With increasing x, the shift of Raman scattering spectra is due to the enhancement of electron–phonon interaction along the c-axis. The contrary variation of infrared in wavenumber comes from the weakening electron–phonon interactions in the ab plane. There is a dramatic variation in resistivity as x increases, which is also caused by increasing carrier concentration and is related to the band shift. For Pr 1-x Sr 1+x CoO 4, both A1g bands shift to low frequency and reach a minimum when x = 0.3 and the resistivity of Pr 0.7 Sr 1.3 CoO 4 is the smallest at room temperature.

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Temperature- and energy-dependent phase shifts of resonant multiple-beam X-ray diffraction in germanium crystals

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273315009006 ◽

2015 ◽

Vol 71 (4) ◽

pp. 460-466 ◽

Cited By ~ 2

Author(s):

Po-Yu Liao ◽

Wen-Chung Liu ◽

Chih-Hao Cheng ◽

Yi-Hua Chiu ◽

Ying-Yu Kung ◽

...

Keyword(s):

Phase Shifts ◽

Anomalous Dispersion ◽

Induced Anisotropy ◽

X Ray Diffraction ◽

Phonon Interaction ◽

X Ray ◽

Electron Phonon Interaction ◽

Multiple Beam ◽

Energy Dependent ◽

Beam Diffraction

This paper reports temperature- and energy-dependent phase shifts of resonant multiple-beam X-ray diffraction in germanium crystals, involving forbidden (002) and weak (222) reflections. Phase determination based on multiple-beam diffraction is employed to estimate phase shifts from (002)-based \{(002)(375)(37\overline{3})\} four-beam cases and (222)-based \{ (222)(\overline{5}3\overline{3})\} three-beam cases in the vicinity of the GeKedge for temperatures from 20 K up to 300 K. The forbidden/weak reflections enhance the sensitivity of measuring phases at resonance. At room temperature, the resonance triplet phases reach a maximum of 8° for the four-beam cases and −19° for the three-beam cases. It is found that the peak intensities and triplet phases obtained from the (002) four-beam diffraction are related to thermal motion induced anisotropy and anomalous dispersion, while the (222) three-beam diffraction depends on the aspherical covalent electron distribution and anomalous dispersion. However, the electron–phonon interaction usually affects the forbidden reflections with increasing temperatures and seems to have less effect on the resonance triplet phase shifts measured from the (002) four-beam diffraction. The resonance triplet phase shifts of the (222) three-beam diffractionversustemperature are also small.

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Optical Spectroscopic Studies of a Soluble Fluorene-Based Conjugated Polymer: A Hydrostatic Pressure and Temperature Study

MRS Proceedings ◽

10.1557/proc-708-bb10.7 ◽

2001 ◽

Vol 708 ◽

Author(s):

S. Guha ◽

J.D. Rice ◽

C. M. Martin ◽

W. Graupner ◽

M. Chandrasekhar ◽

...

Keyword(s):

Hydrostatic Pressure ◽

Conjugated Polymer ◽

Spectroscopic Properties ◽

Spectroscopic Studies ◽

Phonon Interaction ◽

Optical Studies ◽

Strong Electron ◽

Conjugated Molecules ◽

Electron Phonon Interaction ◽

Backbone Conformation

ABSTRACTSpectroscopic properties of conjugated molecules/polymers have varying degrees of sensitivity to backbone conformation. Optical studies are presented as a function of temperature and hydrostatic pressure, using photoluminescence and Raman scattering from two polymers with distinct differences in their backbone conformation, namely, polyfluorene (PF) and ladder type poly(para-phenylene)(m-LPPP). In contrast to the photoluminescence (PL) vibronics in mLPPP, the 0-0 PL vibronic peak in PF shows a red-shift with increasing temperatures. Pressure studies reveal that the PL spectrum of PF red-shifts and broadens with increasing pressures. The phonon lines in PF show an antiresonance effect at higher pressures indicating a strong electron-phonon interaction.

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Crystal structure characterization and electronic structure of a rare-earth-containing Zintl phase in the Yb–Al–Sb family: Yb3AlSb3

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229621005192 ◽

2021 ◽

Vol 77 (6) ◽

Author(s):

Rongqing Shang ◽

An T. Nguyen ◽

Allan He ◽

Susan M. Kauzlarich

Keyword(s):

Crystal Structure ◽

Electronic Structure ◽

Rare Earth ◽

Electronic Structure Calculations ◽

Structure Characterization ◽

Charge Balance ◽

X Ray Diffraction ◽

Zintl Phase ◽

X Ray ◽

Structure Calculations

A rare-earth-containing compound, ytterbium aluminium antimonide, Yb3AlSb3 (Ca3AlAs3-type structure), has been successfully synthesized within the Yb–Al–Sb system through flux methods. According to the Zintl formalism, this structure is nominally made up of (Yb2+)3[(Al1−)(1b – Sb2−)2(2b – Sb1−)], where 1b and 2b indicate 1-bonded and 2-bonded, respectively, and Al is treated as part of the covalent anionic network. The crystal structure features infinite corner-sharing AlSb4 tetrahedra, [AlSb2Sb2/2]6−, with Yb2+ cations residing between the tetrahedra to provide charge balance. Herein, the synthetic conditions, the crystal structure determined from single-crystal X-ray diffraction data, and electronic structure calculations are reported.

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Impact of various reactant concentrations on the morphology and photoluminescence property of synthetic ZnO nanobelts

Modern Physics Letters B ◽

10.1142/s0217984917503377 ◽

2017 ◽

Vol 31 (35) ◽

pp. 1750337

Author(s):

Guoxuan Qin ◽

Yanan Wang ◽

Shentong Mo ◽

Xing Fu ◽

Hui Wang ◽

...

Keyword(s):

Photoluminescence Property ◽

Xrd Analysis ◽

Maximum Temperature ◽

X Ray Diffraction ◽

Light Emitting ◽

X Ray ◽

Light Emitting Devices ◽

Uv Emission ◽

Zno Nanomaterials ◽

Fluorescence Spectrometer

In this paper, ZnO nanobelts have been partially high-quality synthesized employing diverse reactant mass ratios between zinc acetate [Zn(AC)2] and polyvinyl alcohol (PVA) without any catalyst. The maximum temperature required for the whole reaction process is no more than 650[Formula: see text]C. The morphologies of ZnO nanomaterials fabricated from distinct reactant concentrations have been systematically investigated by means of field-emission scanning electron microscopy (FESEM). X-ray diffraction (XRD) analysis identifies that ZnO nanobelts exhibit a typical wurtzite structure. Through fluorescence spectrometer, the photoluminescence (PL) spectra generated by ZnO nanomaterials corresponding to different reactant concentrations have disparate peak intensities and luminescence wavelengths. This phenomenon indicates that novel-synthesized ZnO nanomaterial shows great potential in changing the optical properties of light-emitting devices. In addition, synthetic ZnO nanobelts exhibit excellent UV emission capability.

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Metallic hydrogen with a strong electron-phonon interaction at a pressure of 300–500 GPa

Solid State Communications ◽

10.1016/j.ssc.2017.06.005 ◽

2017 ◽

Vol 262 ◽

pp. 33-39 ◽

Cited By ~ 1

Author(s):

N.N. Degtyarenko ◽

E.A. Mazur ◽

K.S. Grishakov

Keyword(s):

Metallic Hydrogen ◽

Phonon Interaction ◽

Strong Electron ◽

Electron Phonon Interaction

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A new ternary silicide GdFe1−xSi2 (x=0.32): preparation, crystal and electronic structure

Zeitschrift für Naturforschung B ◽

10.1515/znb-2019-0200 ◽

2020 ◽

Vol 75 (1-2) ◽

pp. 217-223

Author(s):

Volodymyr Babizhetskyy ◽

Jürgen Köhler ◽

Yuriy Tyvanchuk ◽

Chong Zheng

Keyword(s):

Electronic Structure ◽

Tight Binding ◽

Structure Type ◽

X Ray Diffraction ◽

Orthorhombic Space Group ◽

X Ray ◽

Arc Melting ◽

Lmto Method ◽

Type Orthorhombic ◽

Crystal And Electronic Structure

AbstractThe title compound was prepared from the elements by arc-melting. The crystal structure was investigated by means of single-crystal X-ray diffraction. It crystallizes in the TbFeSi2 structure type, orthorhombic space group Cmmm, a = 4.0496(8), b = 16.416(2), c = 3.9527(6) Å, Z = 4, R1 = 0.041, wR2 = 0.11 for 207 unique reflections with Io > 2 σ(Io) and 19 refined parameters. The Fe position is not fully occupied and the refinement results in a composition GdFe0.68Si2 in agreement with a chemical analysis. The structure consists of zig-zag chains of Si(1) atoms which are terminally bound to additional Si(2) atoms. For an ordered variant GdFe0.5Si2 the Zintl concept can be applied which results in formal oxidation states Gd3+(Fe2+)0.5Si(1)1−Si(2)3−. The electronic structure of this variant GdFe0.5Si2 was analyzed using the tight-binding LMTO method and the results confirm the simple bonding picture.

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