scholarly journals High-Throughput Computational Search for Half-Metallic Oxides

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2010
Author(s):  
Laalitha S. I. Liyanage ◽  
Jagoda Sławińska ◽  
Priya Gopal ◽  
Stefano Curtarolo ◽  
Marco Fornari ◽  
...  
Keyword(s):  
Density Of States ◽  
High Throughput ◽  
Chemical Space ◽  
A Priori ◽  
Structural Formula ◽  
Inorganic Crystal Structure Database ◽  
Half Metallic ◽  
Half Metals ◽  
Metallic Oxides ◽  
Computational Search

Half metals are a peculiar class of ferromagnets that have a metallic density of states at the Fermi level in one spin channel and simultaneous semiconducting or insulating properties in the opposite one. Even though they are very desirable for spintronics applications, identification of robust half-metallic materials is by no means an easy task. Because their unusual electronic structures emerge from subtleties in the hybridization of the orbitals, there is no simple rule which permits to select a priori suitable candidate materials. Here, we have conducted a high-throughput computational search for half-metallic compounds. The analysis of calculated electronic properties of thousands of materials from the inorganic crystal structure database allowed us to identify potential half metals. Remarkably, we have found over two-hundred strong half-metallic oxides; several of them have never been reported before. Considering the fact that oxides represent an important class of prospective spintronics materials, we have discussed them in further detail. In particular, they have been classified in different families based on the number of elements, structural formula, and distribution of density of states in the spin channels. We are convinced that such a framework can help to design rules for the exploration of a vaster chemical space and enable the discovery of novel half-metallic oxides with properties on demand.

Ab-Initio Investigation of Strain Effects on the Physical Properties of PdVTe Alloy

2021 ◽  
Author(s):  
Khodja Djamila ◽  
Djaafri Tayeb ◽  
Djaafri Abdelkader ◽  
Bendjedid Aicha ◽  
Hamada Khelifa ◽  
...  
Keyword(s):  
Optical Properties ◽  
Density Of States ◽  
Phonon Dispersion ◽  
Electronic Band Structure ◽  
Debye Model ◽  
Full Potential ◽  
Electronic Band ◽  
Metallic Behavior ◽  
Strain Effects ◽  
Half Metallic

The investigations of the strain effects on magnetism, elasticity, electronic, optical and thermodynamic properties of PdVTe half-Heusler alloy are carried out using the most accurate methods to electronic band structure, i.e. the full-potential linearized augmented plane wave plus a local orbital (FP-LAPW + lo) approach. The analysis of the band structures and the density of states reveals the Half-metallic behavior with a small indirect band gap Eg of 0.51 eV around the Fermi level for the minority spin channels. The study of magnetic properties led to the predicted value of total magnetic moment µtot = 3µB, which nicely follows the Slater–Pauling rule µtot = Zt -18. Several optical properties are calculated for the first time and the predicted values are in line with the Penn model. It is shown from the imaginary part of the complex dielectric function that the investigated alloy is optically metallic. The variations of thermodynamic parameters calculated using the quasi-harmonic Debye model, accord well with the results predicted by the Debye theory. Moreover, the dynamical stability of the investigated alloy is computed by means of the phonon dispersion curves, the density of states, and the formation energies. Finally, the analysis of the strain effects reveals that PdVTe alloy preserves its ferromagnetic half metallic behavior, it remains mechanically stable, the ionic nature dominates the atomic bonding, and the thermodynamic and the optical properties keep the same features in a large interval of pressure.

scholarly journals ChemSpaX: Exploration of Chemical Space by Automated Functionalization of Molecular Scaffold

2021 ◽  
Author(s):  
Adarsh Kalikadien ◽  
Evgeny A. Pidko ◽  
Vivek Sinha
Keyword(s):  
Force Field ◽  
High Throughput ◽  
High Throughput Screening ◽  
Chemical Space ◽  
Space Exploration ◽  
Molecular Structures ◽  
Data Driven ◽  
Pincer Complexes ◽  
Cobalt Porphyrin ◽  
Input Structure

<div>Local chemical space exploration of an experimentally synthesized material can be done by making slight structural</div><div>variations of the synthesized material. This generation of many molecular structures with reasonable quality,</div><div>that resemble an existing (chemical) purposeful material, is needed for high-throughput screening purposes in</div><div>material design. Large databases of geometry and chemical properties of transition metal complexes are not</div><div>readily available, although these complexes are widely used in homogeneous catalysis. A Python-based workflow,</div><div>ChemSpaX, that is aimed at automating local chemical space exploration for any type of molecule, is introduced.</div><div>The overall computational workflow of ChemSpaX is explained in more detail. ChemSpaX uses 3D information,</div><div>to place functional groups on an input structure. For example, the input structure can be a catalyst for which one</div><div>wants to use high-throughput screening to investigate if the catalytic activity can be improved. The newly placed</div><div>substituents are optimized using a computationally cheap force-field optimization method. After placement of</div><div>new substituents, higher level optimizations using xTB or DFT instead of force-field optimization are also possible</div><div>in the current workflow. In representative applications of ChemSpaX, it is shown that the structures generated by</div><div>ChemSpaX have a reasonable quality for usage in high-throughput screening applications. Representative applications</div><div>of ChemSpaX are shown by investigating various adducts on functionalized Mn-based pincer complexes,</div><div>hydrogenation of Ru-based pincer complexes, functionalization of cobalt porphyrin complexes and functionalization</div><div>of a bipyridyl functionalized cobalt-porphyrin trapped in a M2L4 type cage complex. Descriptors such as</div><div>the Gibbs free energy of reaction and HOMO-LUMO gap, that can be used in data-driven design and discovery</div><div>of catalysts, were selected and studied in more detail for the selected use cases. The relatively fast GFN2-xTB</div><div>method was used to calculate these descriptors and a comparison was done against DFT calculated descriptors.</div><div>ChemSpaX is open-source and aims to bolster the efforts of the scientific community towards data-driven material</div><div>discovery.</div>

scholarly journals Computational High-Throughput Screening of Polymeric Photocatalysts: Exploring the Effect of Composition, Sequence Isomerism and Conformational Degrees of Freedom

2018 ◽  
Author(s):  
isabelle Heath-Apostolopoulos ◽  
Liam Wilbraham ◽  
Martijn Zwijnenburg
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Degrees Of Freedom ◽  
Chemical Space ◽  
Low Cost ◽  
Computational Screening ◽  
Computational Workflow ◽  
Conformational Degrees Of Freedom

We discuss a low-cost computational workflow for the high-throughput screening of polymeric photocatalysts and demonstrate its utility by applying it to a number of challenging problems that would be difficult to tackle otherwise. Specifically we show how having access to a low-cost method allows one to screen a vast chemical space, as well as to probe the effects of conformational degrees of freedom and sequence isomerism. Finally, we discuss both the opportunities of computational screening in the search for polymer photocatalysts, as well as the biggest challenges.

First-Principles Study of the New Half-Metallic Ferromagnetic Quaternary-Heusler Alloys NaXNO (X=Ca, Sr, Ba)

SPIN ◽  
2020 ◽  
Vol 10 (03) ◽  
pp. 2050022 ◽  
Author(s):  
K. Belkacem ◽  
Y. Zaoui ◽  
S. Amari ◽  
L. Beldi ◽  
B. Bouhafs
Keyword(s):  
Magnetic Properties ◽  
Density Of States ◽  
First Principles ◽  
Density Functional ◽  
Heusler Alloys ◽  
Exchange Potential ◽  
Energy Calculation ◽  
Full Potential ◽  
Electronic Band ◽  
Half Metallic

The first-principles approach based on density functional theory (DFT) and the full-potential linearized augmented plane-wave method were employed to investigate the structural, elastic, electronic and magnetic properties of Na[Formula: see text]NO ([Formula: see text], Sr and Ba) quaternary half-Heusler alloys. The generalized gradient approximation (GGA) as parameterized by Perdew, Burke and Ernzerhof (PBE) and the modified Becke–Johnson exchange potential were used. As far as we know, we present our results which for the first time quantitatively account for the electronic structures and magnetic properties of Na[Formula: see text]NO ([Formula: see text], Sr and Ba) quaternary half-Heusler alloys. From the total energy calculation using three possible atomic configurations ([Formula: see text], [Formula: see text] and [Formula: see text]), it is found that the Na[Formula: see text]NO ([Formula: see text], Sr and Ba) quaternary half-Heusler alloys are more stable in the ferromagnetic [Formula: see text]-phase. From our estimated elastic constants [Formula: see text], it is found that all the considered Heusler alloys are mechanically stable in the [Formula: see text]-phase. We have also investigated the robustness of the half-metallicity with respect to the variation of lattice constants in these alloys. We have found that these alloys are half-metallic ferromagnets (HMFs) with a magnetic moment of 2[Formula: see text][Formula: see text] per formula unit at their equilibrium volumes. The spin-polarized electronic band structure and density of states of these quaternary half-Heusler alloys calculated by GGA (mBJ-GGA) show that the minority spin channels have metallic nature and the majority spin channels have a semiconductor character with half-metallic gaps of 0.49[Formula: see text]eV (2.17[Formula: see text]eV), 0.72[Formula: see text]eV (2.28[Formula: see text]eV) and 0.96[Formula: see text]eV (2.22[Formula: see text]eV) for NaCaNO, NaSrNO and NaBaNO quaternary half-Heusler alloys, respectively. Analysis of the density of states and the spin charge density of these quaternary alloys indicates that their magnetic moments mainly originate from the strong spin-polarization of 2[Formula: see text] states of N atoms and O atoms.

Comprehensive and High‐Throughput Exploration of Chemical Space Using Broadband 19 F NMR‐Based Screening

2020 ◽  
Vol 132 (35) ◽  
pp. 14919-14927
Author(s):  
Andreas Lingel ◽  
Anna Vulpetti ◽  
Tony Reinsperger ◽  
Andrew Proudfoot ◽  
Regis Denay ◽  
...  
Keyword(s):  
High Throughput ◽  
Chemical Space ◽  
19 F Nmr

Spintronics: perspectives for the half-metallic oxides

2004 ◽  
Vol 201 (7) ◽  
pp. 1392-1397 ◽  
Author(s):  
A. M. Haghiri-Gosnet ◽  
T. Arnal ◽  
R. Soulimane ◽  
M. Koubaa ◽  
J. P. Renard
Keyword(s):  
Half Metallic ◽  
Metallic Oxides

Structural and Magnetic Study on the Effect of Substitution of Cobalt by d-Valent Elements of Co2FeSi Heusler Alloy

2016 ◽  
Vol 708 ◽  
pp. 37-41
Author(s):  
Muhammad Noor Syazwan Saimin ◽  
Siti Sumaiyah Sheikh Abdul Aziz ◽  
A.M.M. Ali ◽  
Oskar Hasdinor Hassan ◽  
Muhd Zu Azhan Yahya ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Band Structure ◽  
Fermi Level ◽  
Density Of States ◽  
Magnetic Moment ◽  
Local Magnetic Moment ◽  
Half Metallic ◽  
New States ◽  
Full Heusler

In this paper, the effect of substitution of Co by d-valent elements such as Ag and Pt on electronic structure and magnetic properties of full Heusler type Co2FeSi alloys was investigated. Structural study reveals the presence of a small gap in the minority band structure around the vicinity of the Fermi level on Co2FeSi resulting to half-metallic behaviour. However, CoFeSiAg and CoFeSiPt cannot preserved the half-metalicity due to disappearing of the gap in the minority band structure due to the creation of new states around the Fermi level in the minority density of states. The variation in the magnetic moment of Co2FeSi with change of the atoms was attributed to the change in the local magnetic moment of atoms.

Inverse Magnetoresistance In Manganite/SrTiO3/Co Tunnel Junctions

1999 ◽  
Vol 574 ◽  
Author(s):  
J. M. De Teresa ◽  
A. Barthélémy ◽  
J. P. Contour ◽  
A. Fert ◽  
R. Lyonnet ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Fermi Level ◽  
Spin Polarization ◽  
Density Of States ◽  
High Magnetic Field ◽  
Applied Voltage ◽  
Tunnel Junctions ◽  
Effect Of Temperature ◽  
Half Metallic ◽  
Tunnel Magnetoresistance

AbstractIn La0.7Sr0.3MnO3/SrTiO3/Co tunnel junctions, the half-metallic nature of La0.7Sr0.3MnO3 allows probing the spin polarization of Co. For applied voltage bias around zero volts, an inverse tunnel magnetoresistance is found, indicating the negative spin polarization of Co at the Fermi level as expected from the density of states of the “d” band in Co. The bias dependence of the magnetoresistance reflects the structure of the “d” band density of states of Co. In this article we underline the important consequences for the knowledge of the spin-dependent tunneling in solids brought by these results and describe in detail the effect of temperature and high magnetic field on the magnetoresistance.

Computational search for two-dimensional intrinsic half-metals in transition-metal dinitrides

2017 ◽  
Vol 5 (3) ◽  
pp. 727-732 ◽  
Author(s):  
Junyan Liu ◽  
Zhifeng Liu ◽  
Tielei Song ◽  
Xin Cui
Keyword(s):  
Transition Metal ◽  
First Principles ◽  
Two Dimensional ◽  
Half Metallicity ◽  
2D Material ◽  
Half Metals ◽  
Computational Search

A promising 2D material (1T-TaN2 monolayer) with intrinsic half-metallicity and ferromagnetism has been characterized by a first-principles computational search.

Sign in / Sign up

Export Citation Format

Share Document