Density Functional Calculations on Electronic and Magnetic Properties of Fe-Pt Systems

2005 ◽  
Vol 475-479 ◽  
pp. 3103-3106 ◽  
Author(s):  
You Song Gu ◽  
Jian He ◽  
Zhen Ji ◽  
Xiao Yan Zhan ◽  
Yue Zhang ◽  
...  

The electronic structures and magnetic properties of Fe-Pt systems were calculated by CASTEP codes, which employed density functional theory, generalized gradient approximation (GGA), Perdew Burke Ernzerh exchange correlation, Pulay density-mixing scheme and Ultra Soft pseudo potential. The band structures and density of states (DOS) were calculated, together with band populations and magnetic properties. The calculated results of α-Fe show the validatiy of this method in predication magnetic properties. It is found that as the Pt concentration increases, Fe 4s and 3d electrons decrease while 4p electrons increase, and the magnetic moment of Fe atom increases. Pt atoms also contribute to the magnetic moment due to polarization. The calculated magnetization agrees with experimental values quite well.

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Xueran Liu ◽  
Meijun Han ◽  
Xinjiang Zhang ◽  
Haijun Hou ◽  
Shaoping Pang ◽  
...  

First principle calculations based on density functional theory with the generalized gradient approximation were carried out to investigate the energetic and electronic properties of carbon and boron nitride double-wall hetero-nanotubes (C/BN-DWHNTs) with different chirality and size, including an armchair (n,n) carbon nanotube (CNT) enclosed in (m,m) boron nitride nanotube (BNNT) and a zigzag (n, 0) CNT enclosed in (m, 0) BNNT. The electronic structure of these DWHNTs under a transverse electric field was also investigated. The ability to tune the band gap with changing the intertube distance (di) and imposing an external electric field (F) of zigzag DWHNTs provides the possibility for future electronic and electrooptic nanodevice applications.


2010 ◽  
Vol 09 (06) ◽  
pp. 619-622
Author(s):  
BOTHINA A. HAMAD

In this work, a theoretical study of the structural, electronic and magnetic properties are presented for Mn 0.5 Ni 0.5 alloyed overlayer adsorbed on Cu (001) surface. The calculations were performed using the density functional theory (DFT) and the exchange-correlation potential was treated by the generalized gradient approximation (GGA). The system was fully relaxed except for the central layer, which yields to outward relaxations and inward Mn and Ni surface atoms, respectively in the ferromagnetic and antiferromagnetic configurations. The in-plane ferromagnetic configuration was found to be more stable than the antiferromagnetic one by 25 meV/atom. The local magnetic moments of Mn atoms were found to be about 4 μ B , whereas those of the Ni atoms where found to be 0.46 μ B .


2018 ◽  
Vol 5 (6) ◽  
pp. 180359 ◽  
Author(s):  
Yuya Nagasawa ◽  
Takeshi Koyama ◽  
Susumu Okada

The energetics and geometries of perylene encapsulated in carbon nanotubes (CNTs) have been investigated employing density functional theory using the generalized gradient approximation combined with the van der Waals correction. Our calculations show that the encapsulated perylene molecules possess two metastable molecular conformations with respect to the CNT wall, which are almost degenerate with each other. A standing conformation, with respect to the CNT wall, is the ground state conformation for a semiconducting (19,0)CNT, while a lying conformation is the ground state for a metallic (11,11)CNT. Cooperation and competition between perylene–perylene and perylene–CNT interactions cause these possible perylene conformations inside CNTs. However, the electronic structure of the CNT encapsulating the perylene molecules is found to be insensitive to the molecular conformation.


2016 ◽  
Vol 18 (40) ◽  
pp. 27858-27867 ◽  
Author(s):  
G. L. Gutsev ◽  
K. G. Belay ◽  
K. V. Bozhenko ◽  
L. G. Gutsev ◽  
B. R. Ramachandran

Geometrical and electronic structures of the 3d-metal oxide clusters (FeO)n, (CoO)n, and (NiO)n are computed using density functional theory with the generalized gradient approximation in the range of 1 ≤ n ≤ 10.


2014 ◽  
Vol 1047 ◽  
pp. 41-44
Author(s):  
Mamta Chauhan ◽  
Dinesh Chandra Gupta ◽  
Idris Hamid Bhat

We have performed ab-initio calculations to investigate the structural and electronic behavior of TiN in the stable B1 and high pressure B2 phases using pseudo-potential plane wave approach within the framework of density functional theory. The calculated results show agreement with the experimental data. The present electronic behavior, determined by total energy calculations with generalized gradient approximation for exchange and correlation interactions, is observed to be similar in both B1 and B2 phases showing metallic, covalent as well as ionic bonding of TiN. The investigations in B2 phase need validation experimentally as well as theoretically.


2018 ◽  
Vol 6 (2) ◽  
pp. 53
Author(s):  
Salah Daoud ◽  
Rabie Mezouar ◽  
Abdelfateh Benmakhlouf

The present work aims to investigate the structural parameters and the piezoelectric coefficients of cubic zinc-blende Aluminum phosphide (AlP) under high pressure up to 21 GPa, using plane wave-pseudopotential (PW-PP) approach in the framework of the density functional theory (DFT) and the density functional perturbation theory (DFPT) with the generalized gradient approximation (GGA) for the exchange-correlation functional. The results obtained are analyzed and compared with other data of the literature. The structural parameters and the piezoelectric coefficients calculated here agree well with other data of the literature. We found also that both the direct and converse piezoelectric coefficients increase with increasing pressure up to 21 GPa. 


2008 ◽  
Vol 55-57 ◽  
pp. 857-860 ◽  
Author(s):  
Ekaphan Swatsitang ◽  
A. Pimsawat

ABINIT program package based on Density Functional Theory (DFT) within the Generalized Gradient Approximation (GGA) and plane wave basis set are used to calculate the magnetic properties of Mn doped NiO. It was found that the magnetic properties of Mn doped NiO were changed from anti-ferromagnetic (pure NiO) to ferromagnetism. Increasing the concentrations of Mn, the magnetization of Mn doped NiO were increased (Ni31MnO32 = 66.69 µB, Ni30Mn2O32 = 69.59 µB and Ni29Mn3O32 = 72.42 µB).


2012 ◽  
Vol 588-589 ◽  
pp. 51-54
Author(s):  
Lin Xu ◽  
Zong Lin Liu ◽  
Hong Kuan Yuan

The geometries, stabilities, electronic and magnetic properties of small GdnO3(n=1-5) clusters have been systematically studied by using density functional theory with the generalized gradient approximation. We found that the Gd atoms and O atoms in GdnO3clusters prefer three and two coordination, respectively, which origin from the electronic configurations of Gd and O atoms. The results show that Gd2O3cluster is more stable than its respective neighbors, which is reflected from its high average binding energy and high HOMO-LUMO gap. In addition, we calculate the magnetic properties of GdnO3clusters. The local magnetic moments of the Gd atom in the GdnO3clusters exhibit a weak dependence on the O atoms, which are slightly enhanced with the increasing of the number of Gd atom.


2013 ◽  
Vol 27 (12) ◽  
pp. 1350046
Author(s):  
HAVVA BOGAZ OZISIK ◽  
KEMAL COLAKOGLU ◽  
ENGIN DELIGOZ

The thermodynamic properties of AgB 2 and AuB 2 compounds in AlB 2 and OsB 2-type structures are investigated from first-principles calculations based on density functional theory (DFT) using projector augmented waves (PAW) potentials within the generalized gradient approximation (GGA) for modeling exchange-correlation effects, respectively. Specifically, using the quasi-harmonic Debye model, the effects of pressure and temperature, up to 100 GPa and 1400 K, on the bulk modulus, Debye temperature, thermal expansion, heat capacity and the Grüneisen parameter are calculated successfully and trends are discussed.


RSC Advances ◽  
2018 ◽  
Vol 8 (25) ◽  
pp. 13850-13856 ◽  
Author(s):  
Assa Aravindh Sasikala Devi ◽  
Iman S. Roqan

The structural stability and magnetic properties of a grain boundary (GB) formed by two ZnO single crystals oriented at 45° is investigated by density functional theory, using generalized gradient approximation (GGA) with Hubbard parameter (U).


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