scholarly journals Electron Momentum Density and Phase Transition in ZnS

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
N. Munjal ◽  
M. C. Mishra ◽  
G. Sharma ◽  
B. K. Sharma
Keyword(s):  
Phase Transition ◽  
Density Functional ◽  
Momentum Density ◽  
Compton Profile ◽  
Functional Theory ◽  
Electron Momentum ◽  
Electron Momentum Density ◽  
Atomic Orbitals ◽  
Valence Electron Density ◽  
Good Agreement

The electron momentum density distribution and phase transition in ZnS are reported in this paper. The calculations are performed on the basis of density functional theory (DFT) based on the linear combination of atomic orbitals (LCAO) method. To compare the theoretical Compton profile, the measurement on polycrystalline ZnS has been made using a Compton spectrometer employing 59.54 keV gamma rays. The spherically averaged theoretical Compton profile is in agreement with the measurement. On the basis of equal valence-electron-density Compton profiles, it is found that ZnS is less covalent as compared to ZnSe. The present study suggests zincblende (ZB) to rocksalt (RS) phase transition at 13.7 GPa. The calculated transition pressure is found in good agreement with the previous investigations.

Electron momentum density of hexagonal Zn studied by high-resolution Compton scattering

2021 ◽  
Vol 28 (1) ◽  
pp. 188-195
Author(s):  
Marek Brancewicz ◽  
Andrzej Andrejczuk ◽  
Eugeniusz Żukowski ◽  
Ludwik Dobrzyński ◽  
Yoshiharu Sakurai ◽  
...  
Keyword(s):  
High Resolution ◽  
Density Functional ◽  
Momentum Density ◽  
High Symmetry ◽  
Functional Theory ◽  
High Resolution Data ◽  
Electron Momentum ◽  
Electron Momentum Density ◽  
Better Than

High-resolution (0.12 a.u.) electron momentum density projections (Compton profiles) of a hexagonal Zn single crystal have been measured along five high-symmetry directions in reciprocal space. The experiment was performed with the use of 115.6 keV synchrotron radiation on the BL08W station at SPring-8. The quality of the measured Compton profiles is significantly better than that of previous medium- and high-resolution data. The experimental data were compared with the corresponding theoretical Korringa–Kohn–Rostoker (KKR) and density functional theory (DFT) calculations. Some minor and major differences between the two theoretical band-structure calculations have been observed. However, the good quality experimental results indicate their better agreement with DFT.

First-Principle Study on the Structural Phase Transition, and Electronic Structures of Cobalt under Pressure

2015 ◽  
Vol 729 ◽  
pp. 15-20
Author(s):  
Hong Bo Zhu ◽  
Dun Qiang Tan ◽  
Zhi Huang Xiong
Keyword(s):  
Phase Transition ◽  
Electronic Structures ◽  
Density Functional ◽  
Structural Parameters ◽  
Structural Phase ◽  
First Principles Calculation ◽  
Functional Theory ◽  
Calculated Equilibrium ◽  
Theoretical Results ◽  
Good Agreement

The structural phase transitions and electronic structures of Co are investigated by using the first-principles calculation based on density-functional theory (DFT). Our calculated equilibrium structural parameters of Co are in good agreement with the available experimental data and other theoretical results. The calculated phase transition hcp-Co → fcc-Co at ca. 125.25 GPa. The magnetic moment of hcp-Co and fcc-Co drops to zero at 155 GPa and 77 GPa, respectively.

Compton Profile Study and Electron Momentum Density Reconstruction in Hexagonal Mg

2013 ◽  
Vol 82 (7) ◽  
pp. 074702 ◽  
Author(s):  
Marek Brancewicz ◽  
Maciej Pylak ◽  
Andrzej Andrejczuk ◽  
Eugeniusz Żukowski ◽  
Ludwik Dobrzyński ◽  
...  
Keyword(s):  
Momentum Density ◽  
Compton Profile ◽  
Electron Momentum ◽  
Electron Momentum Density ◽  
Profile Study

Electron momentum density and Compton profile in disordered alloys

2001 ◽  
Vol 62 (12) ◽  
pp. 2191-2197 ◽  
Author(s):  
A. Bansil ◽  
B. Barbiellini ◽  
S. Kaprzyk ◽  
P.E. Mijnarends
Keyword(s):  
Momentum Density ◽  
Compton Profile ◽  
Electron Momentum ◽  
Electron Momentum Density ◽  
Disordered Alloys

Electron Momentum Density of Hexagonal Magnesium Studied by Compton Scattering

2006 ◽  
Vol 112 ◽  
pp. 123-132 ◽  
Author(s):  
Marek Brancewicz ◽  
Henryk Reniewicz ◽  
Andrzej Andrejczuk ◽  
Ludwik Dobrzyński ◽  
Eugeniusz Żukowski ◽  
...  
Keyword(s):  
High Energy ◽  
Momentum Density ◽  
Directional Effect ◽  
Electron Momentum ◽  
Electron Momentum Density ◽  
Cubic Metals ◽  
Medium Resolution ◽  
Small Anisotropy ◽  
Directional Difference ◽  
Good Agreement

Directional Compton profiles of single crystal of hcp magnesium have been measured with scattering vectors along the [10 10], [1120] and [0001] directions in reciprocal space (special directions ΓΜ, ΓΚ, ΓΑ) using high-energy (662 keV) gamma radiation from a 137Cs isotope source. The experimental data were compared with corresponding theoretical Korringa-Kohn-Rostoker (KKR) calculations. The directional difference profiles, both experimental (of medium resolution) and theoretical ones, show very small anisotropy of the electron momentum density in magnesium, 2-3 times lower than in zinc and cadmium single crystals, significantly lower than observed in cubic metals. This small directional effect is in good agreement with Compton 60-keV energy experiments and positron annihilation data presented by other authors.

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