First-Principles Analysis on the Role of Rare-Earth Doping in Affecting Nitrogen Adsorption and Diffusion at Fe Surface Towards Clarified Catalytic Diffusion

2020 ◽  
Author(s):  
X.Z. Dai ◽  
X.R. Yang ◽  
S.H. Zhang ◽  
D.Y. Li
Keyword(s):  
Rare Earth ◽  
First Principles ◽  
Nitrogen Adsorption ◽  
Rare Earth Doping ◽  
And Diffusion

Electronic Properties of Zno Doped by Rare-Earth Elements from First-Principles

2013 ◽  
Vol 690-693 ◽  
pp. 623-626
Author(s):  
Lan Li Chen ◽  
Hong Duo Hu ◽  
Zhi Hua Xiong
Keyword(s):  
Rare Earth ◽  
Fermi Level ◽  
Conduction Band ◽  
First Principles ◽  
Theoretical Explanation ◽  
Rare Earth Doping ◽  
Rare Element ◽  
Rare Elements ◽  
Element Doping ◽  
Strong Hybridization

We perform first-principles calculations to investigate the band structure and density of states of rare-elements doped ZnO. The calculated results show that the shapes of band structures for ZnO by rare-element doping are similar. And the rare-elements incorporation has a little influence on the band gap of the doping system under our considered doping concentration, but after doping, the Fermi level goes into the conduction band, and the electrons from the conduction band minimum to the Fermi level are increasing after rare-earth doping, which means that rare-element doping can change the electrical conductivity of ZnO to a great extent. Meanwhile, it is found that the conduction band near the Fermi level is determined by the rare-element-d states and O-p states, demonstrating as a strong hybridization. This study could provide a theoretical explanation for the factors influencing the properties of ZnO.

Multifunctional Role of Rare Earth Doping in Optical Materials: Nonaqueous Sol–Gel Synthesis of Stabilized Cubic HfO2Luminescent Nanoparticles

ACS Nano ◽  
2013 ◽  
Vol 7 (8) ◽  
pp. 7041-7052 ◽  
Author(s):  
Alessandro Lauria ◽  
Irene Villa ◽  
Mauro Fasoli ◽  
Markus Niederberger ◽  
Anna Vedda
Keyword(s):  
Rare Earth ◽  
Optical Materials ◽  
Sol Gel ◽  
Rare Earth Doping ◽  
Sol Gel Synthesis

Tuning Magnetic Properties of BiFeO3Thin Films by Controlling Rare-Earth Doping: Experimental and First-Principles Studies

2015 ◽  
pp. 150616125012002 ◽  
Author(s):  
Nguyen Hoa Hong ◽  
Ngo Thu Huong ◽  
Tae-Young Kim ◽  
Souraya Goumri-Said ◽  
Mohammed Benali Kanoun
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
First Principles ◽  
Rare Earth Doping

Role of Atomic Size and Valence in Bonding and Diffusion at Metal Surfaces

1992 ◽  
Vol 280 ◽  
Author(s):  
Peter J. Feibelman
Keyword(s):  
Diffusion Barrier ◽  
First Principles ◽  
Metal Surfaces ◽  
Experimental Results ◽  
First Principles Calculations ◽  
Atomic Size ◽  
Self Diffusion ◽  
Chemical Concepts ◽  
And Diffusion

ABSTRACTFirst-principles calculations and corresponding experimental results underline the importance of basic chemical concepts in understanding bonding and diffusion of atoms at and on metal surfaces. Examples discussed include the outward relaxation of clean Be(0001), the separation energies of metal-adatom dimers, concerted substitutional self-diffusion on fcc(001) and (110) surfaces, and adsorption and diffusion barrier sites for adatoms near steps.

Ru Passivated and Ru Doped e-TaN surfaces as Combined Barrier and Liner Material for Copper Interconnects: A First Principles Study

2018 ◽  
Author(s):  
Suresh Natarajan ◽  
Cara-Lena Nies ◽  
Michael Nolan
Keyword(s):  
First Principles ◽  
Film Growth ◽  
Early Stage ◽  
Copper Interconnects ◽  
Liner Material ◽  
Critical Dimensions ◽  
Industry Standard ◽  
Cu Film ◽  
Improved Performance ◽  
And Diffusion

<div>As the critical dimensions of transistors continue to be scaled down to facilitate improved performance and device speeds, new ultrathin materials that combine diffusion barrier and seed/liner properties are needed for copper interconnects at these length scales. Ideally, to facilitate coating of high aspect ratio structures, this alternative barrier+liner material should only consist of one or as few layers as possible. We studied TaN, the current industry standard for Cu diffusion barriers, and Ru, which is a</div><div>suitable liner material for Cu electroplating, to explore how combining these two materials in a barrier+liner material influences the adsorption of Cu atoms in the early stage of Cu film growth. To this end, we carried out first-principles simulations of the adsorption and diffusion of Cu adatoms at Ru-passivated and Ru-doped e-TaN(1 1 0) surfaces. For comparison, we also studied the behaviour of Cu and Ru adatoms at the low index surfaces of e-TaN, as well as the interaction of Cu adatoms with the (0 0 1) surface of hexagonal Ru. Our results confirm the barrier and liner properties of TaN and Ru, respectively while also highlighting the weaknesses of both materials. Ru passivated TaN was found to have improved binding with Cu adatoms as compared to the bare TaN and Ru surfaces.</div><div>On the other hand, the energetic barrier for Cu diffusion at Ru passivated TaN surface was lower than at the bare TaN surface which can promote Cu agglomeration. For Ru-doped TaN however, a decrease in Cu binding energy was found in addition to favourable migration of the Cu adatoms toward the doped Ru atom and unfavourable migration away from it or into the bulk. This suggests that Ru doping sites in the TaN surface can act as nucleation points for Cu growth with high migration barrier preventing agglomeration and allow electroplating of Cu. Therefore Ru-doped TaN is proposed as a candidate for a combined barrier+liner material with reduced thickness.</div>

Effect of cluster-gradient architecture of nanostructured topocomposites on features of tribointeraction with heterophased material

2020 ◽  
pp. 130-135
Author(s):  
D.N. Korotaev ◽  
K.N. Poleshchenko ◽  
E.N. Eremin ◽  
E.E. Tarasov
Keyword(s):  
Wear Resistance ◽  
Titanium Alloy ◽  
Energy Dissipation ◽  
Phase Structure ◽  
Diffusion Processes ◽  
Structural Phase ◽  
High Wear Resistance ◽  
Wear Characteristics ◽  
And Diffusion

The wear resistance and wear characteristics of cluster-gradient architecture (CGA) nanostructured topocomposites are studied. The specifics of tribocontact interaction under microcutting conditions is considered. The reasons for retention of high wear resistance of this class of nanostructured topocomposites are studied. The mechanisms of energy dissipation from the tribocontact zone, due to the nanogeometry and the structural-phase structure of CGA topocomposites are analyzed. The role of triboactivated deformation and diffusion processes in providing increased wear resistance of carbide-based topocomposites is shown. They are tested under the conditions of blade processing of heat-resistant titanium alloy.

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