scholarly journals Propiedades electrónicas y estructurales del Ga1-xCrxAs

2018 ◽  
Vol 42 (162) ◽  
pp. 26
Author(s):  
Nasly Y. Martínez Velásquez ◽  
Jairo Arbey Rodríguez Martínez
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Functional Theory ◽  
Half Metallic ◽  
El Sistema ◽  
Quantum Espresso

Mediante el uso de principios basados en la teoría del funcional de la densidad - DFT (Density Functional Theory) se calcularon las propiedades electrónicas y estructurales del compuesto Ga1-xCrxAs. Empleando el método de ondas planas y la aproximación de pseudopotenciales atómicos ultra suaves se resolvieron las ecuaciones de Kohn-Sham. Para la energía de intercambio y correlación se empleó la aproximación de gradiente generalizado, dentro de la parametrización de Perdew-Burke-Ernzerhof (PBE) tal como está implementada en el código computacional Quantum-Espresso. Al dopar GaAs con impurezas de Cr, el sistema exhibe un comportamiento tipo half-metallic. Dicho material puede ser usado en espintrónica. © 2018. Acad. Colomb. Cienc. Ex. Fis. Nat.

An Investigation of Half-Metallic Ferromagnets Behavior in Hg2CuTi-Type Heusler Alloy Ti2FeAl by Using GGA

2012 ◽  
Vol 535-537 ◽  
pp. 1291-1294 ◽  
Author(s):  
Xiu De Yang ◽  
Bo Wu ◽  
Song Zhang
Keyword(s):  
Density Functional Theory ◽  
Heusler Alloy ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Generalized Gradient Approximation ◽  
Indirect Exchange ◽  
The Density Functional Theory ◽  
Direct Hybridization

By using generalized gradient approximation (GGA) scheme within the density functional theory (DFT), the electronic and magnetic properties of Hg2CuTi-type Heusler alloy Ti2FeAl were investigated. The results reveal that a 100% spin polarization appears at Fermi level (εF) in Ti2FeAl, and is maintained during lattice range of 5.1Å~6.2Å. Ti2FeAl is one of stable Half-Metallic Ferromagnets (HMF) with a spin-minority gap of 0.5 eV at εF and total magnetic moment of 1μB per unit cell. Our studies also indicate that the competition between RKKY-type indirect exchange and direct hybridization of d-electronic atoms plays a dominating role in determining the magnetism.

Magnetic properties of cobalt single layer added on graphene: A density functional theory study

2015 ◽  
Vol 29 (02) ◽  
pp. 1450262 ◽  
Author(s):  
M. Afshar ◽  
H. Doosti
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Single Layer ◽  
Magnetic Ordering ◽  
Polarization Degree ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Cobalt Layer ◽  
Ferromagnetic Ordering

In this paper, we have demonstrated magnetic ordering of single cobalt layer added on graphene using relativistic density functional theory at the level of generalized gradient approximation. We have shown that the single Co layer added on graphene show ferromagnetic ordering with perpendicular alignment to the graphene sheet. In the presence of spin-orbit coupling, a spin-polarization degree of about 92% was found for this quasi-two-dimensional magnetic system where it is shown a nearly half-metallic feature.

scholarly journals Stability and electronic structure of magnesium hydride and magnesium deuteride under high pressure

2021 ◽  
Vol 2145 (1) ◽  
pp. 012026
Author(s):  
Chayaphon Boonchot ◽  
Prutthipong Tsuppayakorn-Aek ◽  
Udomsilp Pinsook ◽  
Thiti Bovornratanaraks
Keyword(s):  
Phase Transition ◽  
Density Functional Theory ◽  
High Pressure ◽  
Electronic Structure ◽  
Density Functional ◽  
Formation Enthalpy ◽  
Band Structures ◽  
Functional Theory ◽  
Superconducting Metal ◽  
Quantum Espresso

Abstract Metal polyhydrides have attracted considerable attention because some of them become a metal under high pressure, and some undergo a phase transition into a superconductor. Some superconducting metal polyhydrides have recently been discovered with a high value of critical temperature (Tc) under pressure. In this research, we calculated the structures of MgH2, MgH3 and MgD3 under pressure between 0-300 GPa in order to determine the formation enthalpy and electronic property of their structures under high pressure by using density functional theory (DFT) based on the Quantum Espresso code. We found that the band structures reveal the metallic character of the compounds under high pressure. The energy band structures of MgHx and MgDx are exactly the same. However, their phonon dispersions are different due to the so-called isotope effect. We determined the composition stability by using the convex hull of Mg, H and the compounds. We found that MgH3 becomes thermodynamically more stable than MgH2 at around 150 GPa. The results of phonons confirm that they are dynamically stable. This finding is served as a basis for future superconducting calculations.

ELECTRONIC STRUCTURES AND MAGNETISM IN Cu-DOPED ZnO MONOLAYER

2013 ◽  
Vol 27 (28) ◽  
pp. 1350204 ◽  
Author(s):  
YUTING PENG ◽  
SHUYI WEI ◽  
CONGXIN XIA ◽  
YU JIA
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
Formation Energy ◽  
Experimental Conditions ◽  
Functional Theory ◽  
Half Metallic ◽  
Doped Zno

In this paper, the electronic structures and magnetic properties of the Cu -doped ZnO monolayer are investigated by means of first-principles methods based on density functional theory. Numerical results show that the Cu dopant can induce the half-metallic ferromagnets in the ZnO monolayer due to the strong p–d coupling. In addition, the semiconductor band gap is also decreased when Zn atom is substituted by Cu atom in the ZnO monolayer. Moreover, the formation energy calculations also indicate that it is energy favorable and relatively easier to incorporate Cu atom into the ZnO monolayer under Zn -rich experimental conditions.

Sign in / Sign up

Export Citation Format

Share Document