scholarly journals The role of intrinsic vacancy defects in the electronic and magnetic properties of Sr3SnO: a first-principles study

RSC Advances ◽  
2017 ◽  
Vol 7 (12) ◽  
pp. 6880-6888 ◽  
Author(s):  
Javaria Batool ◽  
Syed Muhammad Alay-e-Abbas ◽  
Adnan Ali ◽  
Khalid Mahmood ◽  
Shaheen Akhtar ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Stability Diagram ◽  
Vacancy Defects ◽  
Electronic And Magnetic Properties ◽  
O Vacancy ◽  
Formation Energies ◽  
Thermodynamic Stability Diagram

The thermodynamic stability diagram and formation energies of intrinsic vacancy defects in Sr3SnO. Sr and O vacancy containing Sr3SnO is non-magnetic, while ferromagnetism is achieved in Sn deficient Sr3SnO.

Structural, electronic and magnetic properties of S sites vacancy defects graphene/MoS2 van der Waals heterostructures: First-principles study

2021 ◽  
pp. 2150009
Author(s):  
Hari Krishna Neupane ◽  
Narayan Prasad Adhikari
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moment ◽  
First Principles ◽  
Density Functional ◽  
Dominant Role ◽  
Van Der Waals ◽  
Schottky Contact ◽  
Unequal Distribution ◽  
Vacancy Defects ◽  
Electronic And Magnetic Properties

In this work, we investigated the geometrical structures, electronic and magnetic properties of S sites vacancy defects in heterostructure graphene/molybdenum disulphide ((HS)G/MoS[Formula: see text] material by performing first-principles calculations based on spin polarized Density Functional Theory (DFT) method within van der Waals (vdW) corrections (DFT-D2) approach. All the structures are optimized and relaxed by BFGS method using computational tool Quantum ESPRESSO (QE) package. We found that both (HS)G/MoS2 and S sites vacancy defects in (HS)G/MoS2 (D1S–(HS)G/MoS2, U1S–(HS)G/MoS2, 2S–(HS)G/MoS2 and 3S–(HS)G/MoS[Formula: see text] are stable materials, and atoms in defects structures are more compact than in pristine (HS)G/MoS2 structure. From band structure calculations, we found that (HS)G/MoS2, (D1S–(HS)G/MoS2, U1S–(HS)G/MoS2, 2S–(HS)G/MoS2 and 3S–(HS)G/MoS[Formula: see text] materials have [Formula: see text]-type Schottky contact. The Dirac cone is formed in conduction band of the materials mentioned above. The barrier height of Dirac cones from Fermi energy level of (HS)G/MoS2, (D1S–(HS)G/MoS2, U1S–(HS)G/MoS2, 2S–(HS)G/MoS2 and 3S–(HS)G/MoS[Formula: see text] materials have values 0.56[Formula: see text]eV, 0.62[Formula: see text]eV, 0.62[Formula: see text]eV, 0.64[Formula: see text]eV and 0.65[Formula: see text]eV, respectively, which means they have metallic properties. To study the magnetic properties of materials, we have carried out DoS and PDoS calculations. We found that (HS)G/MoS2, D1S–(HS)G/MoS2 and U1S–(HS)G/MoS2 materials have non-magnetic properties, and 2S–(HS)G/MoS2 and 3S–(HS)G/MoS2 materials have magnetic properties. Therefore, the non-magnetic (HS)G/MoS2 changes to magnetic 2S–(HS)G/MoS2 and 3S–(HS)G/MoS2 materials due to 2S and 3S atoms vacancy defects, respectively, in (HS)G/MoS2 material. Magnetic moment obtained in 2S–(HS)G/MoS2 and 3S–(HS)G/MoS2 materials due to the unequal distribution of up and down spin states of electrons in 2s and 2p orbitals of C atoms; 4p, 4d and 5s orbitals of Mo atoms; and 3s and 3p orbitals of S atoms in structures. Magnetic moment of 2S–(HS)G/MoS2 and 3S–(HS)G/MoS2 materials is −0.11[Formula: see text][Formula: see text]/cell and [Formula: see text]/cell, respectively, and spins of 2p orbital of C atoms, 3p orbital of S atoms and 4d orbital of Mo atoms have dominant role to create magnetism in 2S–(HS)G/MoS2 and 3S–(HS)G/MoS2 materials.

Electronic Structure of O-vacancy in High-k Dielectrics and Oxide Semiconductors

2011 ◽  
Vol 1370 ◽  
Author(s):  
Kee Joo Chang ◽  
Byungki Ryu ◽  
Hyeon-Kyun Noh ◽  
Junhyeok Bang ◽  
Eun-Ae Choi
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Device Performance ◽  
Oxide Semiconductors ◽  
Vacancy Defects ◽  
High K ◽  
Quasiparticle Energy ◽  
O Vacancy ◽  
Hybrid Density Functional

ABSTRACTFirst-principles density functional calculations are performed to investigate the electronic properties of O-vacancy defects in high-k HfO2, Si/HfO2 interface, and amorphous oxide semiconductors. The role of O-vacancy in device performance is discussed by comparing the results of the GGA, hybrid density functional, and quasiparticle energy calculations.

scholarly journals The effect of native vacancy defects on electronic and magnetic properties of ZnO:Mn system

2020 ◽  
Vol 34 (21) ◽  
pp. 20502100
Author(s):  
Chun-An Wang ◽  
Jun-Xian Li ◽  
Si-Lie Fu ◽  
Jia-Yi Bao ◽  
Tao Lei ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Nearest Neighbor ◽  
Antiferromagnetic Phase ◽  
Vacancy Defects ◽  
Electronic And Magnetic Properties ◽  
Doped Zno ◽  
O Vacancy ◽  
P Type ◽  
Mn Doped ◽  
Zn Vacancy

In this paper, the plane wave ultra-soft pseudopotential method was performed to analyze the effect of neutral Zn vacancy (V[Formula: see text]) and O vacancy (V[Formula: see text]) on the electronic and magnetic properties of Mn-doped ZnO systems. In a [Formula: see text] ZnO:Mn supercell, the sites of V[Formula: see text] and V[Formula: see text] were set as nearest neighbor, next nearest neighbor and far nearest neighbor relative to Mn site, respectively. The results indicated that V[Formula: see text] is easier to be produced than V[Formula: see text] in the ZnO:Mn system, and both kinds of defects are more likely to be generated in the nearest neighbor of Mn site. Meanwhile, the ZnO:Mn-V[Formula: see text] system is p-type conductive. The farther the distance between V[Formula: see text] and Mn, the better the conductivity of the system. Contrary to V[Formula: see text], the ZnO:Mn-V[Formula: see text] system is n-type conductive. The farther the distance between V[Formula: see text] and Mn, the worse the conductivity of the system. Furthermore, the ZnO:Mn systems containing neutral V[Formula: see text] or V[Formula: see text] are both likely to be in antiferromagnetic phase. However, the presence of V[Formula: see text] will enhance the possibility, while V[Formula: see text] will weaken it.

scholarly journals Tuning Structural, Electronic, and Magnetic Properties of C Sites Vacancy Defects in Graphene/MoS2 van der Waals Heterostructure Materials: A First-Principles Study

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hari Krishna Neupane ◽  
Narayan Prasad Adhikari
Keyword(s):  
Magnetic Properties ◽  
Band Structure ◽  
Density Of States ◽  
First Principles ◽  
Magnetic Moments ◽  
Van Der Waals ◽  
Partial Density ◽  
Vacancy Defects ◽  
Electronic And Magnetic Properties ◽  
Structure Density

In this work, we systematically studied the structure, and electronic and magnetic properties of van der Waals (vdWs) interface Graphene/MoS2 heterostructure (HS-G/MoS2) and C sites vacancy defects in HS-G/MoS2 materials using first-principles calculations. By the structural analysis, we found that nondefects geometry is more compact than defects geometries. To investigate the electronic and magnetic properties of HS-G/MoS2 and C sites vacancy defects in HS-G/MoS2 materials, we have studied band structure, density of states (DOS), and partial density of states (PDOS). By analyzing the results, we found that HS-G/MoS2 is metallic in nature but C sites vacancy defects in HS-G/MoS2 materials have a certain energy bandgap. Also, from the band structure calculations, we found that Fermi energy level shifted towards the conduction band in vacancy defects geometries which reveals that the defected heterostructure is n-type Schottky contacts. From DOS and PDOS analysis, we obtained that the nonmagnetic HS-G/MoS2 material changes to magnetic materials due to the presence of C sites vacancy defects. Right 1C atom vacancy defects (R-1C), left 1C atom vacancy defects (L-1C), centre 1C atom vacancy defects (C-1C), and 2C (1C right and 1C centre) atom vacancy defects in HS-G/MoS2 materials have magnetic moments of −0.75 µB/cell, −0.75 µB/cell, −0.12 µB/cell, and +0.39 µB/cell, respectively. Electrons from 2s and 2p orbitals of C atoms have main contributions for the magnetism in all these materials.

The electronic and magnetic properties of (Mn,N)-codoped ZnO from first principles

2010 ◽  
Vol 108 (11) ◽  
pp. 113924 ◽  
Author(s):  
L. Zhao ◽  
P. F. Lu ◽  
Z. Y. Yu ◽  
X. T. Guo ◽  
Y. Shen ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
First Principles ◽  
Electronic And Magnetic Properties
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