Analysis of Electron Density Distribution in the CuAlO2 System

2020 ◽  
Vol 299 ◽  
pp. 78-83
Author(s):  
A.I. Pogoreltsev ◽  
V.L. Matuhin ◽  
J.D. Plotnikova
Keyword(s):  
Density Distribution ◽  
Electron Density ◽  
Electron Density Distribution ◽  
Covalent Bond ◽  
Transparent Conductive Oxide ◽  
Free Electrons ◽  
Conductive Oxide ◽  
Closed Shells ◽  
Oxygen Bond

The results of earlier studies, using the NQR method 63.65Cu of the compound of the transparent conductive oxide CuAlO2, were used to study the topology of the distribution of the electron density in this compound. It was shown that for Al – O and Cu – Cu pairs, the formation of a bond most likely proceeds according to the type of closed shells, and in the “copper” plane there can be a noticeable number of free electrons. As for the copper – oxygen bond, we can assume the formation of O-Cu-O chains with a covalent bond. The noticeable difference in the character of the electron density distribution in mutually perpendicular planes suggests a certain anisotropy of conductivity in a given compound.

scholarly journals X-Ray scattering at the periphery : forbidden bragg reflections and silicon nanowire arrays

2018 ◽  
Author(s):  
◽  
Jesse Wade Kremenak
Keyword(s):  
Density Distribution ◽  
Electron Density ◽  
Electron Density Distribution ◽  
Crystal Surface ◽  
Structural Information ◽  
Covalent Bond ◽  
Nanowire Arrays ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

In this work, we developed two separate unconventional X-ray scattering techniques that enable us to extract novel information from distinct systems at disparate length scales. We examine the formation of Si nanowire (SiNW) arrays during Ag metal-assisted chemical etching (MACE). The exceptionally rough surface of these nanowire arrays result in very low optical reflectivity, which also makes it extremely challenging to measure the X-ray specular reflection can be measured and utilized to obtain unique structural information about the composition profile of both Ag and Si during the formation of the SiNWs. Secondly, we have discovered a novel interference effect between the crystal surface and the bulk forbidden Bragg reflection that allows - for the first time - both the amplitude and phase of the forbidden reflection to be resolved. The newly attained amplitude and phase information permits one to extract the structure of the non-spherical electron density distribution from diamond crystal structures. We employed X-ray specular reflectivity, a technique conventionally used to study interfaces and surfaces, to examine the non-spherical electron density distribution of bulk Si. We have discovered and demonstrated that the structure of the covalent bond can be ascertained from the weak scattering between the Bragg reflections along the crystal truncation rod. This discovery significantly expands the experimental capability of examining the structure of electron densities, and especially the valence electrons in crystals. Using these novel and unconventional X-ray scattering techniques, we were able to extract valuable information about each system from exceptionally faint signals.

A study on α-RuCl3 crystal structure by scanning tunneling microscopy

1989 ◽  
Vol 47 ◽  
pp. 30-31
Author(s):  
H.-J. Cantow ◽  
H. Hillebrecht ◽  
S. Magonov ◽  
H. W. Rotter ◽  
G. Thiele
Keyword(s):  
Crystal Structure ◽  
Density Distribution ◽  
Scanning Tunneling Microscopy ◽  
Electron Density ◽  
Structure Determination ◽  
Electron Density Distribution ◽  
Scanning Tunneling ◽  
Monoclinic Space Group ◽  
Tunneling Microscopy ◽  
X Ray

From X-ray analysis, the conclusions are drawn from averaged molecular informations. Thus, limitations are caused when analyzing systems whose symmetry is reduced due to interatomic interactions. In contrast, scanning tunneling microscopy (STM) directly images atomic scale surface electron density distribution, with a resolution up to fractions of Angstrom units. The crucial point is the correlation between the electron density distribution and the localization of individual atoms, which is reasonable in many cases. Thus, the use of STM images for crystal structure determination may be permitted. We tried to apply RuCl3 - a layered material with semiconductive properties - for such STM studies. From the X-ray analysis it has been assumed that α-form of this compound crystallizes in the monoclinic space group C2/m (AICI3 type). The chlorine atoms form an almost undistorted cubic closed package while Ru occupies 2/3 of the octahedral holes in every second layer building up a plane hexagon net (graphite net). Idealizing the arrangement of the chlorines a hexagonal symmetry would be expected. X-ray structure determination of isotypic compounds e.g. IrBr3 leads only to averaged positions of the metal atoms as there exist extended stacking faults of the metal layers.

X-ray emission and X-ray photoelectron studies of electron density distribution in Cu(II) complexes with 2-imidazoline nitroxides

2006 ◽  
Vol 47 (3) ◽  
pp. 558-562 ◽  
Author(s):  
L. N. Mazalov ◽  
S. V. Trubina ◽  
G. K. Parygina ◽  
I. M. Oglezneva ◽  
E. A. Aseeva ◽  
...  
Keyword(s):  
Density Distribution ◽  
Electron Density ◽  
Electron Density Distribution ◽  
X Ray

scholarly journals Die zeitliche Änderung der radialen Elektronendichteverteilung beim Theta-Pinch

1963 ◽  
Vol 18 (8-9) ◽  
pp. 895-900
Author(s):  
Franz Peter Küpper
Keyword(s):  
Density Distribution ◽  
Electron Density ◽  
Electron Density Distribution ◽  
Electron Distribution ◽  
Radial Symmetry ◽  
Zero Order ◽  
Time Interval ◽  
Interferometric Method ◽  
Density Distributions ◽  
Theta Pinch

In a θ-pinch the radial symmetry of the electron density distribution as a function of time has been measured by a MACH—ZEHNDER interferometer. In a time interval of 400 nsec during a discharge an image converter made three pictures (exposure times of 10 nsec each) . Up to 100 nsec after the first compression, the experimental results show different density distributions for the cases of trapped parallel and antiparallel magnetic fields. Complete radial symmetry of the electron density distribution was not found.Another interferometric method for measuring the radial symmetry of the electron distribution by observing “zero order” fringes is described.

Sign in / Sign up

Export Citation Format

Share Document