Atomic mobility evaluation and diffusion matrix for fcc_A1 Co–V–W alloys

Examination of the architecture of a semiconductor-based microelectronics device shows that metallic, highly conductive components are an integral part of the miniature circuits. As geometries become increasingly small (e.g. at the sub-micron level) the structure at critical interfaces influences the electrical performance to a greater extent. Accordingly metal-semiconductor junctions have significant technological importance, in addition to any natural scientific interest associated with the bonding of two unlike materials. This article reviews some of our recent work on this topic, with particular emphasis on the reactions which can occur either during fabrication of the interface or upon heating in conjunction with device processing or prolonged service.The simplest system consists of an elemental metal and an elemental semiconductor, silicon being the most important example of the latter. Consideration of phase equilibria indicates that such an interface is thermodynamically unstable: upon heating either a reaction can occur to produce a compound phase (i.e. a silicide), or mutual dissolution of the elements within each other takes place to achieve saturated solid solution compositions. Reference to the appropriate binary phase diagram allows prediction of the result if local equilibrium is achieved. Thus although an atomically abrupt metal-semiconductor interface might be grown under specialized circumstances, this situation can be expected to be unusual and moreover it is not stable to elevated temperatures when atomic mobility and diffusion are rapid.

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Evaluating atomic mobility and interdiffusivity based on two-dimensional diffusion simulations and diffusion triple experiments

Scripta Materialia ◽

10.1016/j.scriptamat.2020.07.026 ◽

2020 ◽

Vol 188 ◽

pp. 124-129

Author(s):

Cheng-Hui Xia ◽

Shi-Lin Xia ◽

Ying Li ◽

Xiao-Gang Lu

Keyword(s):

Atomic Mobility ◽

Two Dimensional ◽

Dimensional Diffusion ◽

Diffusion Triple ◽

And Diffusion

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Exact representation of the asymptotic drift speed and diffusion matrix for a class of velocity-jump processes

Journal of Differential Equations ◽

10.1016/j.jde.2015.08.043 ◽

2016 ◽

Vol 260 (1) ◽

pp. 401-426 ◽

Cited By ~ 2

Author(s):

Corrado Mascia

Keyword(s):

Jump Processes ◽

Exact Representation ◽

Diffusion Matrix ◽

Drift Speed ◽

Velocity Jump ◽

And Diffusion

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Atomic mobility in Titanium grade 5 (Ti6Al4V)

Journal of Mining and Metallurgy Section B Metallurgy ◽

10.2298/jmmb180620030g ◽

2019 ◽

Vol 55 (1) ◽

pp. 65-77 ◽

Cited By ~ 2

Author(s):

W. Gierlotka ◽

G. Lothongkum ◽

B. Lohwongwatana ◽

C. Puncreoburt

Keyword(s):

Heat Treatment ◽

Wide Spectrum ◽

Atomic Mobility ◽

Modern Material ◽

Grade 5 ◽

Packed Structure ◽

Titanium Grade ◽

Material Information ◽

And Diffusion ◽

Good Agreement

Titanium grade 5 (Ti6Al4V) is a modern material that can be found in a wide spectrum of applications, from medicine to aircraft industry. The commercial alloy is a mix of a body centered cubic structure (BCC_A2) and a hexagonal closed packed structure (HCP_A3). It is obvious, that heat treatment of the alloy will change a ratio between BCC_A2 and HCP_A3 and, as a consequence, properties of a material. Information about mobility of atoms in both crystal structures allows simulations and predictions of structures? behavior during the heat treatment and diffusion. In this work the atomic mobility in liquid, BCC_A2, and HCP_A3 phases of ternary alloy Al ? Ti ? V were obtained based on available literature information. Comparison between simulations and experiments shows a good agreement, hence it can be concluded that proposed set of kinetic parameters can be used for predictions and simulations of Titanium grade 5 heat treatment.

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Meridional Circulation, Turbulence, and Diffusion Processes in Stars

International Astronomical Union Colloquium ◽

10.1017/s0252921100080477 ◽

1976 ◽

Vol 32 ◽

pp. 109-116 ◽

Cited By ~ 1

Author(s):

S. Vauclair

Keyword(s):

Convection Zone ◽

Diffusion Processes ◽

Meridional Circulation ◽

Diffusion Time ◽

Work In Progress ◽

First Results ◽

Stellar Envelopes ◽

And Diffusion ◽

Turbulence And Diffusion ◽

Hr Diagram

This paper gives the first results of a work in progress, in collaboration with G. Michaud and G. Vauclair. It is a first attempt to compute the effects of meridional circulation and turbulence on diffusion processes in stellar envelopes. Computations have been made for a 2 Mʘstar, which lies in the Am - δ Scuti region of the HR diagram.Let us recall that in Am stars diffusion cannot occur between the two outer convection zones, contrary to what was assumed by Watson (1970, 1971) and Smith (1971), since they are linked by overshooting (Latour, 1972; Toomre et al., 1975). But diffusion may occur at the bottom of the second convection zone. According to Vauclair et al. (1974), the second convection zone, due to He II ionization, disappears after a time equal to the helium diffusion time, and then diffusion may happen at the bottom of the first convection zone, so that the arguments by Watson and Smith are preserved.

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