scholarly journals First-Principles Study on the Cu/Fe Interface Properties of Ternary Cu-Fe-X Alloys

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3112
Author(s):  
Yufei Wang ◽  
Min Li ◽  
Haiyan Gao ◽  
Jun Wang ◽  
Baode Sun

The supersaturated Fe in Cu is known to reduce the electrical conductivity of Cu severely. However, the precipitation kinetics of Fe from Cu are sluggish. Alloying is one of the effective ways to accelerate the aging precipitation of Cu-Fe alloys. Nucleation plays an important role in the early stage of aging. The interface property of Cu/γ–Fe is a key parameter in understanding the nucleation mechanism of γ-Fe, which can be obviously affected with the addition of alloying elements. In this paper, first principles calculations were carried out to investigate the influence of alloying elements on the interface properties, including the geometric optimizations, interfacial energy, work of adhesion and electronic structure. Based on the previous research, 14 elements including B, Si, P, Al, Ge, S, Mg, Ag, Cd, Sn, In, Sb, Zr and Bi were selected for investigation. Results showed that all these alloying elements tend to concentrate in the Cu matrix with the specific substitution position of the atoms determined by the binding energy between Fe and alloy element (X). The bonding strength of the Cu/γ-Fe interface will decrease obviously after adding Ag, Mg and Cd, while a drop in interfacial energy of Cu/γ–Fe will happen when alloyed with Al, B, S, P, Si, Ge, Sn, Zr, Bi, Sb and In. Further study of the electronic structure found that Al and Zr were not effective alloying elements.

1994 ◽  
Vol 357 ◽  
Author(s):  
M. W. Finnis ◽  
C. Kruse ◽  
U. SchÖnberger

AbstractWe discuss the recent first principles calculations of the properties of interfaces between metals and oxides. This type of calculation is parameter-free, and exploits the density functional theory in the local density approximation to obtain the electronic structure of the system. At the same time the equilibrium atomic structure is sought, which minimises the excess energy of the interface. Up to now calculations of this type have been made for a few model interfaces which are atomically coherent, that is with commensurate lattices. Examples are Ag/MgO and Nb/Al2O3. In these cases it has been possible to predict the structures observed by high resolution electron microscopy. The calculations are actually made in a supercell geometry, in which there are alternating nanolayers of metal and ceramic. Because of the effectiveness of metallic screening in particular, the interfaces between the nanolayers do not interfere much with each other.Besides the electronic structure of the interface, such calculations have provided values of the ideal work of adhesion. Electrostatic image forces in conjunction with the elementary ionic model provide a simple framework for understanding the results.An important role of such calculations is to develop intuition about the nature of the bonding, including the effects of charge transfer, which has formerly only been described in an empirical way. It may then be possible to build atomistic models of the metal/ceramic interaction which have a sound physical basis and can be calibrated against ab initio results. Simpler models are necessary if larger systems, including misfit dislocations and other defects, are to be simulated, with a view to understanding the atomic processes of growth and failure. Another area in which ab initio calculations can be expected to contribute is in the chemistry of impurity segregation and its effect at interfaces. Such theoretical tools are a natural partner to the experimental technique of high resolution electron energy loss spectroscopy for studying the local chemical environment at an interface.


2013 ◽  
Vol 38 (18) ◽  
pp. 4495-4501 ◽  
Author(s):  
Sanwu Wang ◽  
Yingdi Liu ◽  
Michael R. Halfmoon ◽  
Hongli Dang ◽  
Christine A. Rittenhouse ◽  
...  

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1681
Author(s):  
Mingjie Wang ◽  
Guowei Zhang ◽  
Hong Xu ◽  
Yizheng Fu

In this study, the cohesive energy, interfacial energy, electronic structure, and bonding of Mg2Si (111)/Mg3Sb2 (0001) were investigated by using the first-principles method based on density functional theory. Meanwhile, the mechanism of the Mg3Sb2 heterogeneous nucleation potency on Mg2Si grains was revealed. The results indicated that the Mg3Sb2 (0001) slab and the Mg2Si (111) slab achieved bulk-like characteristics when the atomic layers N ≥ 11, and the work of adhesion of the hollow-site (HCP) stacking structure (the interfacial Sb atom located on top of the Si atom in the second layer of Mg2Si) was larger than that of the other stacking structures. For the four HCP stacking structures, the Sb-terminated Mg3Sb2/Si-terminated Mg2Si interface with a hollow site showed the largest work of adhesion and the smallest interfacial energy, which implied the strongest stability among 12 different interface models. In addition, the difference in the charge density and the partial density of states indicated that the electronic structure of the Si-HCP-Sb interface presented a strong covalent, and the bonding of the Si-HCP-Mg interface and the Mg-HCP-Sb interface was a mixture of a covalent bond and a metallic bond, while the Mg-HCP-Mg interfacial bonding corresponded to metallicity. As a result, the Mg2Si was conducive to form a nucleus on the Sb-terminated-hollow-site Mg3Sb2 (0001) surface, and the Mg3Sb2 particles promoted the Mg2Si heterogeneous nucleation, which was consistent with the experimental expectations.


2005 ◽  
Vol 475-479 ◽  
pp. 3123-3126
Author(s):  
Yu Fang Lin ◽  
Dongliang Zhao ◽  
Xin Lin Wang

Employing the first principles discrete variational method(DVM), we investigated the electronic structure of LaNi5 hydrogen storage alloys containing various alloying elements, M=Mn,Fe,Co. The results showed that s electrons of H mainly interact with s electrons of hydride-non-forming element Ni, though hydride forming element La have stronger affinity to hydrogen atom. And alloying elements strengthened the bond between B-H, so decreased the capacity of doped-system.


1999 ◽  
Vol 14 (7) ◽  
pp. 2824-2829 ◽  
Author(s):  
Y. Song ◽  
R. Yang ◽  
D. Li ◽  
W. T. Wu ◽  
Z. X. Guo

The influence of ternary additions Cr, Fe, Mn, Ni, Zr, Nb, Mo, Hf, Ta, Si, Ga, Ge, In, and Sb, as well as the anti-site defects of both Ti and Al, on lattice parameters of TiAl were studied by the first principles electronic structure calculations with a discrete variational cluster method. The results of the calculation show that the effect of ternary additions on the distortion of TiAl lattice varies with the substitution behavior of the individual alloying element involved. The addition of alloying elements in TiAl causes a change in the electronic structure and the density of states of the system and results in variation of the bond strength between the atoms. The total and partial density of states (DOS) of binary TiAl and of ternary TiAl–M, M = Cr, Zr, and Sb, etc., were comparatively examined. The relationship between the DOS and the bond strength is discussed. The present work suggests that the origin of the lattice distortion of the ternary TiAl–M systems lies in the variation of the electronic structure.


2017 ◽  
Vol 31 (12) ◽  
pp. 1750138 ◽  
Author(s):  
Yuan Hua Lin ◽  
Chuang Chuang Tong ◽  
Yong Pan ◽  
Wan Ying Liu ◽  
Ambrish Singh

In this work, we have applied the first-principles calculations to investigate the structural stability, elastic properties and electronic structure of Mo2FeB2 with alloying elements Cr, Ni and Mn. The calculated cohesive energy shows that Cr, Ni and Mn prefer to occupy the Fe atom of Mo2FeB2. However, only when Mn is doped at the Mo atom of Mo2FeB2, it is converted from dynamic unstable state to stable state. The calculated elastic modulus shows that Mo2FeB2 will have better mechanical properties when alloying elements are at Fe site instead of Mo site. Moreover, Cr addition can improve the volume deformation resistance of Mo2FeB2, Mn addition can improve the shear deformation resistance for Mo2FeB2. The calculated B/G ratio shows that Ni addition can improve the brittleness of borides. Furthermore, the hardness of Mo2FeB2 can be enhanced by adding Cr and Mn element. The calculated electronic structure indicates that the increasing of elastic modulus is attributed to the formation of Cr–B and Mn–B covalent bonds.


Author(s):  
Jianbo Qi ◽  
Hong Guo ◽  
Guangxin Wu ◽  
Jieyu Zhang ◽  
Kuochih Chou

We use the first principles plane wave pseudopotential method calculated the mechanical property with respect to the quenching and aging process of uranium-1.3 wt.% titanium alloy, including the elastic modulus, bulk modulus, Young’s shear modulus and the ideal tensile strength, meanwhile deeply research on the mechanical property mechanism changes through t-he electronic structure. The results show that t-he elastic modulus and ideal tensile strength of quenching state are 198GP and 21.2GP, respectively, and slightly improving through aging treatment. The variation of energy and electronic structure of uranium-titanium solid solution in process of quenching indicate the phase transition from γ phase (cubic structure) to α′ phase (orthorhombic structure) lead to improve to the mechanical property. In process of aging, at the beginning the metastable supersaturated solid solution appears Guinier-Preston (G.P) zones, which are aggregate of solute atoms in the uranium matrix, further improving the tensile strength. Then U2Ti (hexagonal structure) precipitates present in over-aged process as a result of decomposition of metastable α′ phase and reduce the tensile strength. The result shows that the G.P/matrix and precipitate/matrix interfaces have ideal work of adhesion are 15.2eV and 12.5eV, respectively. Our results demonstrate theoretically quenching and aging heat treatment strengthening effect of uranium-titanium alloy.


2015 ◽  
Vol 29 (29) ◽  
pp. 1550182 ◽  
Author(s):  
Xiao-Min He ◽  
Zhi-Ming Chen ◽  
Lei Huang ◽  
Lian-Bi Li

Combining advanced transmission electron microscopy with high-precision first-principles calculations, the properties of Si(111)/[Formula: see text]/6H-SiC(0001) (Si-terminated and C-terminated) heterojunction interface, such as work of adhesion, geometry property, electronic structure and bonding nature, are studied. The experiments have demonstrated that interfacial orientation relationships of Si(111)/[Formula: see text]/6H-SiC(0001) heterojunction are [Formula: see text]-[Formula: see text] and Si(111)/6H-SiC(0001). Compared with C-terminated interface, Si-terminated interface has higher adhesion and less relaxation extent.


2014 ◽  
Vol 52 (12) ◽  
pp. 1025-1029
Author(s):  
Min-Wook Oh ◽  
Tae-Gu Kang ◽  
Byungki Ryu ◽  
Ji Eun Lee ◽  
Sung-Jae Joo ◽  
...  

2018 ◽  
Author(s):  
Suresh Natarajan ◽  
Cara-Lena Nies ◽  
Michael Nolan

<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>


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