Adsorption of rare-earth atoms onl silicon carbide nanotube: a density-functional study

2014 ◽  
Vol 28 (19) ◽  
pp. 1450154
Author(s):  
Zhiwei An ◽  
Jiang Shen
Keyword(s):  
Silicon Carbide ◽  
Rare Earth ◽  
Density Functional ◽  
Binding Energies ◽  
Functional Study ◽  
Hollow Site ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Metal Atoms ◽  
Silicon Carbide Nanotube

In this paper, we investigate the adsorption of a series of rare-earth (RE) metal atoms ( La , Pr , Nd , Sm and Eu ) on the pristine zigzag (8, 0) silicon carbide nanotube ( SiCNT ) using density functional theory (DFT). Main focuses are placed on the stable adsorption sites, the corresponding binding energies, and the modified electronic properties of the SiC nanotubes due to the adsorbates. A single RE atom prefers to adsorb strongly at the hollow site with relatively high binding energy (larger than 1.0 eV). Due to the rolling effect of single-walled SiCNTs , the inside configurations are more stable than the outside ones. For RE-adsorbed systems, the adsorption of metal atoms induces certain impurity states within the band gap of the pristine SiCNT . Furthermore, we analyze there exists hybridizations between RE-5d, 6s, C -2p and Si -3p orbitals for the RE atom adsorption on the SiCNTs .

STRUCTURES, ELECTRONIC AND MAGNETIC PROPERTIES OF C20 FULLERENES DOPED TRANSITION METAL ATOMS M@C20 (M = Fe, Co, Ti, V)

2010 ◽  
Vol 21 (12) ◽  
pp. 1469-1477 ◽  
Author(s):  
M. SAMAH ◽  
B. BOUGHIDEN
Keyword(s):  
Density Functional Theory ◽  
Magnetic Moment ◽  
Density Functional ◽  
Binding Energies ◽  
Functional Theory ◽  
Magnetic Dipoles ◽  
Metal Atoms ◽  
Transition Metal Atoms ◽  
Semiconductor Behavior ◽  
Co Doped

Structures, binding energies, magnetic and electronic properties endohedrally doped C 20 fullerenes by metallic atoms ( Fe , Co , Ti and V ) have been obtained by pseudopotential density functional theory. All M @ C 20, except Co @ C 20, are more stable than the undoped C 20 cage. The magnetic moment values are 1 and 2μB. These values and semiconductor behavior give to these compounds interesting feature in several technological applications. Titanium doped C 20 has a same magnetic moment than the isolated Ti atom. Hybridization process in the Co doped C 20 fullerene is most strong than in other doped cages. Electrical and magnetic dipoles calculated in the iron doped C 20 are very strong compared with other clusters.

First-Principles Analysis on Interaction between Dopant (Ga, Sb) and Contamination Metal Atoms in Ge Crystals

2013 ◽  
Vol 205-206 ◽  
pp. 417-421
Author(s):  
Tatsunori Yamato ◽  
Koji Sueoka ◽  
Takahiro Maeta
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Binding Energies ◽  
Functional Theory ◽  
Substitutional Site ◽  
Metal Impurities ◽  
Metal Atoms ◽  
Total Energies ◽  
Group 3

The lowest energetic configurations of metal impurities in 4throw (Sc - Zn), 5throw (Y - Cd) and 6throw (Hf - Hg) elements in Ge crystals were determined with density functional theory calculations. It was found that the substitutional site is the lowest energetic configuration for most of the calculated metals in Ge. The most stable configurations of dopant (Ga, Sb) - metal complexes in Ge crystals were also investigated. Following results were obtained. (1) For Ga dopant, 1st neighbor T-site is the most stable for metals in group 3 to 7 elements while substitutional site next to Ga atom is the most stable for metals in group 8 to 12 elements. (2) For Sb dopant, substitutional site next to Sb atom is the most stable for all calculated metals. Binding energies of the interstitial metalMiwith the substitutional dopantDswere obtained by the calculated total energies. The calculated results for Ge were compared with those for Si.

CO2 Adsorption on the B12N12 Nanocage Encapsulated with Alkali Metals: A Density Functional Study

NANO ◽  
2019 ◽  
Vol 14 (03) ◽  
pp. 1950034
Author(s):  
Ximin Liang ◽  
Qiyan Zhang ◽  
Qinfu Zhao ◽  
He Zhao ◽  
Yifan Feng ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Density Functional ◽  
Alkali Metals ◽  
Large Change ◽  
Functional Study ◽  
Functional Theory ◽  
Metal Atoms ◽  
Adsorption Of Co ◽  
Physical And Chemical ◽  
Homo Lumo

Density functional theory (DFT) calculations have been carried out to study the capacity of the B[Formula: see text]N[Formula: see text] nanocage encapsulated with alkali metals (Li, Na, K) for the CO2 adsorption and activation. It is found that after encapsulating alkali metals, the alkali metal atoms are closer to one side of clusters instead of exactly lying at the center, and a considerable charge transfers from the inner alkali metal atoms to the B[Formula: see text]N[Formula: see text] cage. Besides, the HOMO–LUMO gap (HLG) values of Li@B[Formula: see text]N[Formula: see text], Na@B[Formula: see text]N[Formula: see text] and K@B[Formula: see text]N[Formula: see text] are decreased to about 6[Formula: see text]eV, being much smaller than that of the pristine B[Formula: see text]N[Formula: see text]. Although the geometry structure parameters and the energy differences of M06-2X are slightly different from the ones of [Formula: see text]B97X-D, some identical results of two kinds of functional can be obtained. CO2 can be adsorbed chemically and physically on majority bonds of all the clusters, except for some bonds with large change in bond length and bond indices. The encapsulation of alkali-metal atoms may enhance the physical and chemical adsorption of CO2 on the surface of the clusters, in which Na@B[Formula: see text]N[Formula: see text] and K@B[Formula: see text]N[Formula: see text] are the most powerful physical and chemical adsorbent for CO2, respectively.

PLANE-WAVE PSEUDOPOTENTIAL DENSITY FUNCTIONAL THEORY PERIODIC SLAB CALCULATIONS OF NO ADSORPTION ON Ag(001) SURFACE

2010 ◽  
Vol 09 (04) ◽  
pp. 701-709
Author(s):  
H. AGHAIE ◽  
M. R. GHOLAMI ◽  
F. KHAZALI ◽  
K. ZARE ◽  
M. MONAJJEMI ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Density Functional Theory ◽  
Plane Wave ◽  
Density Functional ◽  
Hollow Site ◽  
Generalized Gradient ◽  
No Adsorption ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Generalized Gradient Approximation

Plane-wave pseudopotential density functional theory (DFT) periodic slab calculations were performed using the generalized gradient approximation (GGA) to investigate the adsorption of nitric oxide (NO) on the (001) surface of Ag . We examined three different adsorption sites perpendicular with respect to the surface and a position that the axis of NO molecule was tilted from the upright. The adsorption of NO in the fourfold hollow site was favored, with a binding energy of 45.47 kJ/mol.

scholarly journals Magnetism in Au-Supported Planar Silicene

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2568
Author(s):  
Mariusz Krawiec ◽  
Agnieszka Stępniak-Dybala ◽  
Andrzej Bobyk ◽  
Ryszard Zdyb
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Binding Energies ◽  
Magnetic Ground State ◽  
Functional Theory ◽  
Antiferromagnetic Ordering ◽  
Metal Atoms ◽  
Transition Metal Atoms ◽  
Ferromagnetic Structure

The adsorption and substitution of transition metal atoms (Fe and Co) on Au-supported planar silicene have been studied by means of first-principles density functional theory calculations. The structural, energetic and magnetic properties have been analyzed. Both dopants favor the same atomic configurations with rather strong binding energies and noticeable charge transfer. The adsorption of Fe and Co atoms do not alter the magnetic properties of Au-supported planar silicene, unless a full layer of adsorbate is completed. In the case of substituted system only Fe is able to produce magnetic ground state. The Fe-doped Au-supported planar silicene is a ferromagnetic structure with local antiferromagnetic ordering. The present study is the very first and promising attempt towards ferromagnetic epitaxial planar silicene and points to the importance of the substrate in structural and magnetic properties of silicene.

scholarly journals Water Molecular Adsorption on the Low-Index Pt Surface: A Density Functional Study

2018 ◽  
Vol 18 (2) ◽  
pp. 195 ◽  
Author(s):  
Wahyu Tri Cahyanto ◽  
Aris Haryadi ◽  
Sunardi Sunardi ◽  
Abdul Basit ◽  
Yulin Elina
Keyword(s):  
Charge Transfer ◽  
Density Functional ◽  
Interaction Strength ◽  
Interaction Mechanism ◽  
Functional Study ◽  
Electrostatic Model ◽  
Geometrical Structures ◽  
Functional Theory ◽  
Miller Index ◽  
Adsorption Sites

We report the different way to explain the nature of water molecule (H2O) adsorption on the platinum (Pt) surfaces with low Miller index, i.e., (100), (110) and (111). Here, we perform periodic density functional theory (DFT) calculations to analyze the correlation between water-surface bonding strength and the observed charge transfer occurring in the systems. The results show that Pt-H2O interaction strength at the most stable adsorption sites, i.e., the atop site for each surfaces, follows the order of H2O/Pt(110) > H2O/Pt(100) > H2O/Pt(111). This order has the same pattern with the order of observed charge transfer contributed to the bonding formation. The differences in adsorption geometrical structures in these three surfaces are suggested to responsible for the order of bond strength since Coulomb interaction plays dominant roles in our electrostatic model. Furthermore, H2O-Pt interaction mechanism, which occurs through water 3a1 orbital releasing electron density (charge) followed by Pt-O bonding formation, is clarified.

FIRST PRINCIPLES STUDY OF CYTOSINE ADSORPTION ON GRAPHENE

2009 ◽  
Vol 08 (01n02) ◽  
pp. 5-8 ◽  
Author(s):  
YONG-HUI ZHANG ◽  
KAI-GE ZHOU ◽  
KE-FENG XIE ◽  
CAI-HONG LIU ◽  
HAO-LI ZHANG ◽  
...  
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Binding Energies ◽  
Pristine Graphene ◽  
Functional Theory ◽  
Metal Atoms ◽  
Order Of Magnitude ◽  
Doped Graphene ◽  
Co Doped

The adsorption of cytosine on graphene surface is studied using density functional theory with local density approximation. The cytosine is physisorbed onto graphene through π–π interaction, with a binding energy around -0.39 eV. Due to the weak interaction, the electronic properties of graphene show little change upon adsorption. The cytosine/graphene interaction can be strongly enhanced by introducing metal atoms. The binding energies increase to -0.60 and -2.31 eV in the presence of Li and Co atoms, respectively. The transport behavior of an electric sensor based on Co -doped graphene shows a sensitivity one order of magnitude higher than that of a similar device using pristine graphene. This work reveals that the sensitivity of graphene-based bio-sensors could be drastically improved by introducing appropriate metal atoms.

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