Electronic Structure of Quaternary Chalcogenide Ag2In2Ge(Si)S6 Single Crystals and the Influence of Replacing Ge by Si: Experimental X-Ray Photoelectron Spectroscopy and X-Ray Diffraction Studies and Theoretical Calculations

2013 ◽  
Vol 5 (4) ◽  
pp. 316-327 ◽  
Author(s):  
A. H. Reshak ◽  
O. Y. Khyzhun ◽  
I. V. Kityk ◽  
A. O. Fedorchuk ◽  
H. Kamarudin ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Theoretical Calculations ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Durga Sankar Vavilapalli ◽  
Ambrose A. Melvin ◽  
F. Bellarmine ◽  
Ramanjaneyulu Mannam ◽  
Srihari Velaga ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
First Principle ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Principle Calculations ◽  
Photodegradation Efficiency

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

Mixed Metal Oxide Interfaces: An Experimental and Theoretical Assessment of Secondary Metal Influences in Metal Impregnated Aluminas

1994 ◽  
Vol 368 ◽  
Author(s):  
M. Malaty ◽  
D. Singh ◽  
R. Schaeffer ◽  
S. Jansen ◽  
S. Lawrence
Keyword(s):  
Photoelectron Spectroscopy ◽  
Theoretical Calculations ◽  
Mixed Metal Oxide ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Mixed Metal ◽  
Metal Interactions ◽  
Metal Metal ◽  
Bimetallic System

ABSTRACTStudies of the mixed-metal interface in metal impregnated alumina have indicated the possibility of much metal-metal and metal-substrate interaction. Studies were carried out on NiCu/Al2O3 system which was evaluated to develop a better understanding of the forces that drive modification of the catalytic selectivity of Ni in the presence of Cu. Electron Paramagnetic Resonance (EPR), Powder X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD) and theoretical calculations were carried out on this bimetallic system, using Ni,Ag/Al2O3 as a reference as Ni shows negligible electron perturbation on co-adsorbance with Ag onto alumina. XRD results indicate that gross modification of the electronic fields of Ni and Cu are due to direct coupling and intercalation into the alumina matrix. As a result of this phenomena, these materials may form a good base for the development of novel ceramics based on mixed-metal interactions where the intermetallic perturbations are driven by the substrate effects.

Single crystal growth and magnetic properties of Co-doped ZnNb2O6

2019 ◽  
Vol 33 (23) ◽  
pp. 1950274
Author(s):  
Ying Liu ◽  
Dapeng Xu ◽  
Huamin Yu ◽  
Tian Cui ◽  
Liang Li
Keyword(s):  
Magnetic Properties ◽  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Physical Property Measurement System ◽  
Physical Property ◽  
X Ray Diffraction ◽  
Zone Method ◽  
X Ray ◽  
Structure Formula ◽  
Property Measurement

The columbite structure [Formula: see text] single crystals have been successfully grown by using the optical floating zone method. The as-grown crystals are characterized by X-ray diffraction (XRD), Raman spectroscopy (RS) and X-ray photoelectron spectroscopy (XPS). All these analyses show that the doping Co ions do not disturb the structure of columbite [Formula: see text] and some [Formula: see text] ions are substituted by transition metal [Formula: see text] ions without any other impurities. The magnetic properties of as-grown [Formula: see text] crystals have been investigated using Physical Property Measurement System (PPMS). The effective magnetic moment of [Formula: see text] crystals is [Formula: see text], indicating that [Formula: see text] ions present in [Formula: see text] single crystals are in mixed HS and LS states. The ferromagnetic, antiferromagnetic and paramagnetic characters of as-grown crystals are also discussed.

scholarly journals Crystal structure, homogeneity range and electronic structure of rhombohedral γ-Mn5Al8

2017 ◽  
Vol 232 (7-9) ◽  
Author(s):  
Srinivasa Thimmaiah ◽  
Zachary Tener ◽  
Tej N. Lamichhane ◽  
Paul C. Canfield ◽  
Gordon J. Miller
Keyword(s):  
Crystal Structure ◽  
Phase Diagram ◽  
Electronic Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Homogeneity Range ◽  
X Ray Diffraction ◽  
X Ray ◽  
Eds Analysis

AbstractThe γ-region of the Mn–Al phase diagram between 45 and 70 at.% Al was re-investigated by a combination of powder and single crystal X-ray diffraction as well as EDS analysis to establish the distribution of Mn and Al atoms. Single crystals of γ-Mn

Electronic structure of (MePh3P)2[NiII(bdtCl2)2]·2(CH3)2SO and (MePh3P)[NiIII(bdtCl2)2] (bdtCl2 = 3,6-dichlorobenzene-1,2-dithiolate)

2021 ◽  
Vol 77 (6) ◽  
Author(s):  
Julia Adamko Koziskova ◽  
Yu-Sheng Chen ◽  
Su-Yin Grass ◽  
Yu-Chun Chuang ◽  
I-Jui Hsu ◽  
...  
Keyword(s):  
Electronic Structure ◽  
High Resolution ◽  
Theoretical Calculations ◽  
Nickel Complexes ◽  
Oxidation States ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Absorption ◽  
Bond Character ◽  
Density Modeling

High-resolution X-ray diffraction experiments, theoretical calculations and atom-specific X-ray absorption experiments were used to investigate two nickel complexes, (MePh3P)2[NiII(bdtCl2)2]·2(CH3)2SO [complex (1)] and (MePh3P)[NiIII(bdtCl2)2] [complex (2)]. Combining the techniques of nickel K- and sulfur K-edge X-ray absorption spectroscopy with high-resolution X-ray charge density modeling, together with theoretical calculations, the actual oxidation states of the central Ni atoms in these two complexes are investigated. Ni ions in two complexes are clearly in different oxidation states: the Ni ion of complex (1) is formally NiII; that of complex (2) should be formally NiIII, yet it is best described as a combination of Ni2+ and Ni3+, due to the involvement of the non-innocent ligand in the Ni—L bond. A detailed description of Ni—S bond character (σ,π) is presented.

scholarly journals Electronic structure and chemical bond nature in Cs2NpO2Cl4

2017 ◽  
Vol 32 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Yury Teterin ◽  
Konstantin Maslakov ◽  
Mikhail Ryzhkov ◽  
Anton Teterin ◽  
Kirill Ivanov ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Binding Energy ◽  
Energy Range ◽  
Valence Band ◽  
Chemical Bond ◽  
Photoelectron Spectroscopy ◽  
Theoretical Calculations ◽  
Molecular Orbitals ◽  
X Ray ◽  
Outer Valence

On the basis of the X-ray photoelectron spectroscopy data and results of theoretical calculations for the NpO2Cl4 (D4h) cluster, the electronic structure and the chemical bond nature in , was done in the binding Cs2NpO2Cl4 single crystal, containing the neptunyl group NpO2 energy range of 0 eV to ~35 eV. The filled Np 5f electronic states were established to form in the valence band of Cs2NpO2Cl4. This was attributed to the direct participation of the Np 5f electrons in the chemical bonding. The Np 6p electrons were shown to participate in formation of both the inner valence band (~15 eV-~35 eV) and the outer valence band (0 eV-~15 eV). The filled Np 6p and the O 2s, Cl 3s electronic shells were found to make the largest contribution to the formation of the inner valence molecular orbitals. The molecular orbitals composition and the sequence order in the binding energy range 0 eV-~35 eV in Cs2NpO2Cl4, were established. For the first time the quantitative scheme of molecular orbitals for the NpO2Cl4 cluster in the binding energy range 0 eV-~35 eV, was built. This scheme reflects neptunium close environment in the studied compound and is fundamental for both understanding the chemical bond nature in Cs2NpO2Cl4 and the interpretation of other X-ray spectra of Cs2NpO2Cl4. The contributions to the chemical binding for the NpO2Cl4 cluster were evaluated to be: the outer valence molecular orbitals contribution - 73 %, and the inner valence molecular orbitals contribution - 27 %.

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