scholarly journals Ab initio calculation of the local magnetic moment in titanium doped zinc oxide with a corrected-band-gap scheme

2012 ◽  
Vol 111 (7) ◽  
pp. 07C301 ◽  
Author(s):  
Bin Shao ◽  
Hong Liu ◽  
Jian Wu ◽  
Xu Zuo
Keyword(s):  
Zinc Oxide ◽  
Ab Initio ◽  
Band Gap ◽  
Magnetic Moment ◽  
Ab Initio Calculation ◽  
Local Magnetic Moment

scholarly journals Origin of the Low Magnetic Moment in Fe2AlTi: An Ab Initio Study

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1732 ◽  
Author(s):  
Martin Friák ◽  
Anton Slávik ◽  
Ivana Miháliková ◽  
David Holec ◽  
Monika Všianská ◽  
...  
Keyword(s):  
Ab Initio ◽  
Magnetic Moment ◽  
Energy Surface ◽  
Magnetic Moments ◽  
Local Magnetic Moment ◽  
Spin Configuration ◽  
Spin Effects ◽  
Order Of Magnitude ◽  
Huge Impact ◽  
Insight Into

The intermetallic compound Fe 2 AlTi (alternatively Fe 2 TiAl) is an important phase in the ternary Fe-Al-Ti phase diagram. Previous theoretical studies showed a large discrepancy of approximately an order of magnitude between the ab initio computed magnetic moments and the experimentally measured ones. To unravel the source of this discrepancy, we analyze how various mechanisms present in realistic materials such as residual strain effects or deviations from stoichiometry affect magnetism. Since in spin-unconstrained calculations the system always evolves to the spin configuration which represents a local or global minimum in the total energy surface, finite temperature spin effects are not well described. We therefore turn the investigation around and use constrained spin calculations, fixing the global magnetic moment. This approach provides direct insight into local and global energy minima (reflecting metastable and stable spin phases) as well as the curvature of the energy surface, which correlates with the magnetic entropy and thus the magnetic configuration space accessible at finite temperatures. Based on this approach, we show that deviations from stoichiometry have a huge impact on the local magnetic moment and can explain the experimentally observed low magnetic moments.

Ab initio calculation of magnetic properties of p-block element doped ZnO

RSC Advances ◽  
2014 ◽  
Vol 4 (85) ◽  
pp. 45598-45602 ◽  
Author(s):  
Palash Nath ◽  
Anirban Chakraborti ◽  
D. Sanyal
Keyword(s):  
Magnetic Properties ◽  
Ab Initio ◽  
Magnetic Moment ◽  
Ab Initio Calculation ◽  
Effective Magnetic Moment ◽  
Block Element ◽  
System P ◽  
Doped Zno

Effective magnetic moment for Zn54O53X (X = B, C, N, F, Al, Si, P, Cl, Ga, Ge, As) system.

The effect of the SnO2 substrate on the band gap and magnetic proprieties of MgH2 ultra-thin films: Ab-initio calculation

2019 ◽  
Vol 127 ◽  
pp. 27-34
Author(s):  
E. Salmani ◽  
M. Rouchdi ◽  
A. Endichi ◽  
E. Benchafia ◽  
H. Ez-Zahraouy ◽  
...  
Keyword(s):  
Thin Films ◽  
Ab Initio ◽  
Band Gap ◽  
Ab Initio Calculation

scholarly journals Unveiling orbital coupling at the CoPc/Bi(111) surface by ab initio calculations and photoemission spectroscopy

RSC Advances ◽  
2017 ◽  
Vol 7 (82) ◽  
pp. 52143-52150
Author(s):  
Zhaofeng Liang ◽  
Haoliang Sun ◽  
Kongchao Shen ◽  
Jinbang Hu ◽  
Bo Song ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Magnetic Moment ◽  
Local Magnetic Moment ◽  
Photoemission Spectroscopy

Orbital coupling is revealed at the CoPc/Bi(111) interface with the local magnetic moment retained in CoPc.

scholarly journals AB INITIO CALCULATION OF ADSORPTION POSITION EFFECT ON MAGNETIZATION REDISTRIBUTION IN P-DOPED SILICENE

2021 ◽  
Author(s):  
Aleksandr Prokhorenko ◽  
Yuri Gnidenko ◽  
Yuri Chibisov ◽  
Yuri Chibisova
Keyword(s):  
Binding Energy ◽  
Magnetic Moment ◽  
Diffusion Barrier ◽  
Phosphorus Atom ◽  
Ab Initio Calculation ◽  
Position Effect ◽  
Local Magnetic Moment ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
Phosphorus Diffusion

The behavior (substitution and adsorption) of a phosphorus atom on the surface of silicene is studied using quantum mechanical calculations. The most favorable positions, binding energy and activation of the phosphorus diffusion barrier have been established. The change in the local magnetic moment of the phosphorus atom is described depending on its position and the position of the surrounding silicon elements.

Optical band gap of SrTcO3 from first-principles calculations

2014 ◽  
Vol 28 (06) ◽  
pp. 1450049 ◽  
Author(s):  
Cheng-Min Dai ◽  
Chun-Lan Ma
Keyword(s):  
Band Structure ◽  
Band Gap ◽  
Magnetic Moment ◽  
Optical Band Gap ◽  
Tight Binding ◽  
Local Magnetic Moment ◽  
Exchange Constant ◽  
Generalized Gradient ◽  
Direct Band ◽  
State Band

Although there are intensive studies on technetium oxide SrTcO 3 recently, its ground-state band structure has never been given and no consensus on its band gap is obtained. We use the generalized gradient approximation (GGA) with on-site Coulomb corrections (GGA + U) method to study its band structure and the optical band gap. A series of on-site interaction U and J values are employed in the calculations and the concomitant evolutions of the electronic structure, local magnetic moment of technetium ( Tc ), the exchange constant and the Néel temperature are investigated. The inter-site exchange constant between antiferromagnetic Tc atoms through medium oxygen is found to increase firstly and then decrease with an increasing U, in agreement with the trend obtained by tight-binding method. The appropriate on-site U and J values are calibrated by comparing the calculated local magnetic moment of Tc with the experimental value. It is found that when U = 2.3 eV, J = 0.3 eV are included for Tc 4d in GGA + U calculations, the local magnetic moment of Tc in orthorhombic SrTcO 3 is 2.01 μB, the same as the experimental value obtained at 4 K. The calculated band structure shows that the band gap is a direct band gap with a magnitude of 1.61 eV.

scholarly journals THE STUDY OF GRAPHENE BAND GAP USING HATREE FOCK METHOD IN MOLECULAR SCALE

2020 ◽  
Vol 3 (1) ◽  
pp. 24
Author(s):  
Siti Alaa ◽  
Muhammad Fajrin ◽  
Eva Nurhaliza ◽  
Dian Wijaya Kurniawidi ◽  
Susi Rahayu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Ab Initio ◽  
Band Gap ◽  
Ab Initio Calculation ◽  
Computational Study ◽  
Basis Set ◽  
Ab Initio Method ◽  
Energy Band Gap ◽  
Advanced Material ◽  
Molecular Scale

Graphene is known as an advanced material that has good electrical conductivity and heat conductivity. To understand the nature of graphene it is necessary to calculate the energy, band gap and vibrate frequency at the nanoscale. One method that can be used is the ab initio calculation using the Hatree-Fock method. In this research, we performed a computational study of the electronic properties of grapheme within RHF/STO-3G basis set in different cluster molecules.  From this study we get band gap for graphene in ab initio level, have a consistant value around zero.  Using ab initio method, we can obtain a deeper understanding about the graphene behaviour at the molecular scale.

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