Magnetic ground state, field-induced transitions, electronic structure, and optical band gap of the frustrated antiferromagnet GeCo2O4

2019 ◽  
Vol 99 (13) ◽  
Author(s):  
P. Pramanik ◽  
S. Ghosh ◽  
P. Yanda ◽  
D. C. Joshi ◽  
S. Pittala ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Ground State ◽  
Optical Band Gap ◽  
Magnetic Ground State

Magnetic Ground State and Electronic Structure Calculations of PbMnO3 Using DFT

2014 ◽  
Vol 895 ◽  
pp. 420-423 ◽  
Author(s):  
Sathya Sheela Subramanian ◽  
Baskaran Natesan
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Fermi Level ◽  
Ground State ◽  
Density Functional ◽  
Electronic Structure Calculations ◽  
Magnetic Ground State ◽  
Electronic Band ◽  
Structure Calculations ◽  
Centrosymmetric Structure

Structural optimization, magnetic ground state and electronic structure calculations of tetragonal PbMnO3have been carried out using local density approximation (LDA) implementations of density functional theory (DFT). Structural optimizations were done on tetragonal P4mm (non-centrosymmetric) and P4/mmm (centrosymmetric) structures using experimental lattice parameters and our results indicate that P4mm is more stable than P4/mmm. In order to determine the stable magnetic ground state of PbMnO3, total energies for different magnetic configurations such as nonmagnetic (NM), ferromagnetic (FM) and antiferromagnetic (AFM) were computed for both P4mm and P4/mmm structures. The total energy results reveal that the FM non-centrosymmetric structure is found to be the most stable magnetic ground state. The electronic band structure, density of states (DOS) and the electron localization function (ELF) were calculated for the stable FM structure. ELF revealed the distorted non-centrosymmetric structure. The band structure and DOS for the majority spins of FM PbMnO3showed no band gap at the Fermi level. However, a gap opens up at the Fermi level in minority spin channel suggesting that it could be a half-metal and a potential spintronic candidate.

scholarly journals Electronic structure and optical band gap of CoFe2O4 thin films

2012 ◽  
Vol 101 (16) ◽  
pp. 161902 ◽  
Author(s):  
A. V. Ravindra ◽  
P. Padhan ◽  
W. Prellier
Keyword(s):  
Thin Films ◽  
Electronic Structure ◽  
Band Gap ◽  
Optical Band Gap

scholarly journals Magnetic Ground State and Electronic Structure of Binary Mn2Sb Compound from Ab Initio Calculations

Proceedings ◽  
2020 ◽  
Vol 67 (1) ◽  
pp. 15
Author(s):  
Evgenii D. Chernov ◽  
Alexey V. Lukoyanov
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Ground State ◽  
Spin Projection ◽  
Magnetic Ground State ◽  
First Order Phase Transition ◽  
Magnetocaloric Properties ◽  
Ab Initio Approach ◽  
Long Range Ordering ◽  
First Order Phase

Manganese antimonide Mn2−xMxSb, where M is a 3d transition metal, is a prominent binary material due to its high Curie temperature and magnetocaloric properties accompanying the M-induced first-order phase transition for various compositions. In this work, we employed a modern ab initio approach to analyze the magnetic ground state and electronic structure of Mn2Sb for various types of long-range ordering. In the electronic structure of Mn2Sb, it was found to possess the semi-metallic properties with a gap in the minority spin projection.

Electronic Structure and Ground State Properties of A4[Ag4O4] (A=Na, K and Rb): A First-Principles Study

2013 ◽  
Vol 665 ◽  
pp. 43-48
Author(s):  
Rajagopalan Umamaheswari ◽  
M. Yogeswari ◽  
G. Kalpana
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Ground State ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
First Principles Calculation ◽  
Partial Density ◽  
Electronic Band ◽  
Ground State Properties

The first-principles calculation within density functional theory is used to study in detail the electronic structure and ground state properties of alkali-metal oxoargenates A4[Ag4O4] (A= Na, K and Rb). The total energies calculated within the atomic sphere approximation (ASA) were used to determine the ground state properties such as equilibrium lattice parameter, c/a ratio, bulk modulus and cohesive energy. The theoretically calculated equilibrium lattice constants values are in well agreement with the available experimental values. The electronic band structures, total and partial density of states are calculated. The result of electronic band structure shows that the KAgO and RbAgO are direct band gap semiconductors with their gap lying between the Γ-Γ points, whereas NaAgO is found to be an indirect band gap semiconductor with its gap lying between Z-Γ points.

Optical band gap hierarchy in a magnetic oxide: Electronic structure of NiFe2O4

2012 ◽  
Vol 86 (20) ◽  
Author(s):  
Q. - C. Sun ◽  
H. Sims ◽  
D. Mazumdar ◽  
J. X. Ma ◽  
B. S. Holinsworth ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Optical Band Gap ◽  
Magnetic Oxide

scholarly journals First-principles investigation of transport and magnetism

2021 ◽  
Author(s):  
◽  
Aditya Putatunda
Keyword(s):  
Electronic Structure ◽  
Ground State ◽  
First Principles ◽  
Density Functional ◽  
Magnetic Energy ◽  
Band Model ◽  
Magnetic Ground State ◽  
Critical Material ◽  
Theoretical Concepts ◽  
Quantum Critical

Study of the quantum mechanical nature of a material provides invaluable understanding of its underlying mechanisms governing their fascinating novel properties. Density functional based first-principles methods provide us with the necessary tools to approximate the Schrodinger's equation for many-electron periodic solids. Starting from the atomic position of their constituent atoms, using one of the most accurate methods of all-electron calculations, here in this thesis, I present my investigations of several such different materials in light of these novel phenomena. In the first chapter, I have discussed the basics of this tool and other theoretical concepts that work in the background in order to obtain reliant and consistent results. The results on each of these materials have been arranged around the following six chapters. The second chapter, in its two sections, I demonstrated these methods via two materials: a) the widely known industrial compound TiO2 where I addressed the long standing theory versus experiment disparity of the energy ordering of its two most used polymorphs. Our results, like most of the previous theoretical studies gave anatase as its ground state. In the next section, I investigated the recently synthesized layered monoclinic material: NaSbSe2. The results on its superior electronic and transport property shows its potential as a thermoelectric (TE) candidate. The investigation of TE properties in next chapter focusses on the Lorenz number where a certain widely used prescription for its approximation has been closely examined. Comparing against our first-principles based transport results on few well-known TEs as well as the ideal single parabolic band model, I found that for some materials the prescription works well within acceptable deviations. However, for TEs with complex band structure the deviations are too big which suggests precaution to its use since efficient TEs are often marked by such complex electronic structures only. The following chapters explore magnetism. Starting with the discussion of the pervoskite compound MnSeO3, we found our results to be predicting its true magnetic ground state order. The study of its energetics and electronic structure, in comparison to its non-magnetic analogue ZnSeO3, its magnetic nature was determined to be of local moment nature. Showing unconventional structural properties for a pervoskite compound, doping and spin-wave dispersion investigations will probably be useful. In the next two chapters, I focus on the novel material Sr3Ru2O7. Widely considered as a classic quantum critical material, I discuss why it is important to understand the nature of fluctuations associated with its quantum critical properties. For this purpose, it is important to know the low-energy metastable states in competition with its ground state. The first-principles investigation based survey yielded the striped E-type antiferromagnetic state that lies closest to the ground state. The magnetic-energy ordering in combination to its electronic structure properties, e.g. the density of states suggest its magnetism to be of itinerant nature. My results on the electronic transport indicates that only this striped E-type ordered state carries a distinct anisotropy among its in-plane conductivity components. This result is particularly important since the material Sr3Ru2O7 is experimentally known to display a similar transport anisotropy of the same order under specific magnetic field.

Magnetic ground state in novel valence fluctuating compound Ce2RuGe: Electronic structure investigations

2020 ◽  
Vol 514 ◽  
pp. 167142
Author(s):  
Andrzej Ślebarski ◽  
Józef Deniszczyk ◽  
Elena Murashova ◽  
Dariusz Kaczorowski
Keyword(s):  
Electronic Structure ◽  
Ground State ◽  
Magnetic Ground State ◽  
Structure Investigations
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