Ab Initio Core-Level Shifts in Metallic Alloys

1995 ◽  
Vol 408 ◽  
Author(s):  
Vincenzo Fiorentini ◽  
Michael Methfessel ◽  
Sabrina Oppo
Keyword(s):  
Ab Initio ◽  
Density Functional ◽  
Core Level ◽  
Alloy Formation ◽  
Core Hole ◽  
Final State ◽  
Density Response ◽  
Ordered Intermetallic ◽  
Level Shifts

AbstractCore-level shifts and core-hole screening effects in alloy formation are studied ab initio by constrainedl-density-functional total-energy calculations. For our case study, the ordered intermetallic alloy MgAu, final-state effects are essential to account for the experimental Mg 1s shift, while they are negligible for Au 4f. We explain the differences in the screening by analyzing the calculated charge density response to the core hole perturbation.

ENHANCED SCREENING OF CORE HOLES AT TRANSITION-METAL SURFACES

1995 ◽  
Vol 02 (02) ◽  
pp. 197-201 ◽  
Author(s):  
M. METHFESSEL ◽  
D. HENNIG ◽  
M. SCHEFFLER
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Density Functional ◽  
Core Level ◽  
Level Shift ◽  
Core Hole ◽  
Initial State ◽  
Functional Theory ◽  
Level Shifts

Ab initio calculations based on density-functional theory were used to obtain surface core-level shifts for the 4d transition metals and silver in the initial-state model and in the full-impurity formulation, giving an unambiguous separation into initial state and screening terms. This shows that the screening of the core hole is substantially better at the surface than in the bulk for a transition metal. For Ag, an opposite and even larger effect is found, showing the central role of d-electron screening in the surface core-level shift of the transition metals.

scholarly journals Impact of Nano-Scale Distribution of Atoms on Electronic and Magnetic Properties of Phases in Fe-Al Nanocomposites: An Ab Initio Study

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1059 ◽  
Author(s):  
Ivana Miháliková ◽  
Martin Friák ◽  
Yvonna Jirásková ◽  
David Holec ◽  
Nikola Koutná ◽  
...  
Keyword(s):  
Ab Initio ◽  
Density Functional ◽  
Nearest Neighbor ◽  
Magnetic Moments ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Α Phase ◽  
Ordered Intermetallic ◽  
Random Structures ◽  
The Impact

Quantum-mechanical calculations are applied to examine magnetic and electronic properties of phases appearing in binary Fe-Al-based nanocomposites. The calculations are carried out using the Vienna Ab-initio Simulation Package which implements density functional theory and generalized gradient approximation. The focus is on a disordered solid solution with 18.75 at. % Al in body-centered-cubic ferromagnetic iron, so-called α -phase, and an ordered intermetallic compound Fe 3 Al with the D0 3 structure. In order to reveal the impact of the actual atomic distribution in the disordered Fe-Al α -phase three different special quasi-random structures with or without the 1st and/or 2nd nearest-neighbor Al-Al pairs are used. According to our calculations, energy decreases when eliminating the 1st and 2nd nearest neighbor Al-Al pairs. On the other hand, the local magnetic moments of the Fe atoms decrease with Al concentration in the 1st coordination sphere and increase if the concentration of Al atoms increases in the 2nd one. Furthermore, when simulating Fe-Al/Fe 3 Al nanocomposites (superlattices), changes of local magnetic moments of the Fe atoms up to 0.5 μ B are predicted. These changes very sensitively depend on both the distribution of atoms and the crystallographic orientation of the interfaces.

AB-INITIO CALCULATION OF THE INITIAL- AND FINAL-STATE EFFECTS ON CORE LEVEL SHIFTS AT TRANSITION METAL SURFACES

1993 ◽  
Vol 07 (01n03) ◽  
pp. 542-545
Author(s):  
D. HENNIG ◽  
M. METHFESSEL ◽  
M. SCHEFFLER
Keyword(s):  
Transition Metal ◽  
Core Level ◽  
Level Shift ◽  
Full Potential ◽  
Initial State ◽  
Final State ◽  
State Approximation ◽  
Transition Metal Surface ◽  
Lmto Method ◽  
Level Shifts

The surface core-level shift at a transition metal surface can be calculated in two different ways using the initial-state approximation or using a more involved approach which includes screening of the photo-created core hole. Our calculated results obtained using the full-potential LMTO method for the close packed surfaces of all 4d transition metals within the initial state picture can be well explained by standard arguments.

The role of exchange–correlation functional on the description of multiferroic properties using density functional theory: the ATiO3 (A = Mn, Fe, Ni) case study

RSC Advances ◽  
2016 ◽  
Vol 6 (103) ◽  
pp. 101216-101225 ◽  
Author(s):  
Renan Augusto Pontes Ribeiro ◽  
Sergio Ricardo de Lazaro ◽  
Carlo Gatti
Keyword(s):  
Density Functional Theory ◽  
Ab Initio ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Multiferroic Properties ◽  
Exchange Correlation

In this study, ab initio density functional theory calculations were performed on ATiO3 (A = Mn, Fe, Ni) materials for multiferroic applications.

Core-level shifts from density-functional computations

1993 ◽  
Vol 47 (19) ◽  
pp. 12992-12994 ◽  
Author(s):  
Luca Pedocchi ◽  
Nino Russo ◽  
Dennis R. Salahub
Keyword(s):  
Density Functional ◽  
Core Level ◽  
Level Shifts ◽  
Density Functional Computations

Final State Core Level Shifts in Supported and Free Metal Particles

1988 ◽  
Vol 148 (1) ◽  
pp. 121-128 ◽  
Author(s):  
N. J. Castellani ◽  
D. B. Leroy
Keyword(s):  
Core Level ◽  
Metal Particles ◽  
Final State ◽  
Level Shifts ◽  
Free Metal

Final-state effects in surface core-level shifts

1993 ◽  
Vol 47 (20) ◽  
pp. 13590-13593 ◽  
Author(s):  
A. Nilsson ◽  
A. Stenborg ◽  
H. Tillborg ◽  
K. Gunnelin ◽  
N. Mårtensson
Keyword(s):  
Core Level ◽  
Final State ◽  
Level Shifts
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