Atomic scale calculations of tungsten surface binding energy and beryllium-induced tungsten sputtering

Yang, Xueming; Hassanein, A.

doi:10.1016/j.apsusc.2013.12.129

Cited by 37 publications

(25 citation statements)

References 26 publications

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“…The maximum energy transfer ratio of atoms of interest and maximum transferring energy from incident particle with an energy of 75 eV are summarized in Table 1. Since the surface binding energy of tungsten is 8.8 − 11.75 eV [20,21], the maximum transferring energy of 75 eV helium to tungsten (6.3 eV) is insufficient for yielding sputtering, while the maximum transferring energy to iron (18.7 eV) is sufficient for yielding sputtering. Furthermore, a part of molybdenum mask plate is also exposed to plasma, and the maximum transferring energy of 75 eV helium to molybdenum (11.5 eV) is marginal for yielding sputtering.…”

Section: Discussionmentioning

confidence: 99%

Surface morphology in tungsten and RAFM steel exposed to helium plasma in PSI-2

et al. 2017

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Impact of the helium plasma exposure on the surface modification in tungsten and RAFM (Reduced Activation Ferritic/Martensitic) steel have been investigated on the linear plasma device PSI-2 assuming the condition of DEMO first wall. In tungsten, a nanoscale undulating surface structure, which has a periodic arrangement, is formed under low temperature conditions below fuzz nanostructure formation threshold ∼ 1000 K. Interval and direction of the undulation shows dependence on the crystal orientation. A large variation in surface level up to 200 nm has been observed among grains at a fluence of 3 × 10 26 He/m 2 showing dependence of the surface erosion rate on the crystal orientation. The {100} plane in which the undulating surface structure is not formed shows the highest erosion rate. This significant erosion is due to the multistage sputtering through impurity. In RAFM steel, sponge-like nanostructure is developed and it grows with increasing helium fluence beyond 1 µm. In the sponge-like nanostructure, a composition change from the base material is observed in which the tungsten ratio increases while the iron ratio decreases showing differences in sputtering ratio depending on the atomic mass.

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Section: Discussionmentioning

confidence: 99%

Surface morphology in tungsten and RAFM steel exposed to helium plasma in PSI-2

et al. 2017

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“…The mass of atoms detached, in the same period of time, for each material is dependent on how strongly they are attached to the other atoms, meaning how large their surface binding energy is. The surface binding energy of W and Au is E bindingW =11.75 eV and E bindingAu =4.13 eV, respectively [37,38]. As we would like to compare in a dimensionless way, the behavior of the physical quantities involved in our system, we notice that the ratio of these two energies ( ).…”

Section: Characterization Of the Desorption Mechanismmentioning

confidence: 99%

Energy exchange between atoms with a quartz crystal μ-balance

et al. 2018

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We propose an experimental method to fully characterize the energy exchange of particles during the physical vapor deposition (PVD) process of thin surface layers. Our approach is based on the careful observation of perturbations of the oscillation frequency of a quartz crystal μ-balance induced by the particles' interaction. With this technique it is possible to measure the momentum exchange of the atoms during the evaporation process and determine the ideal evaporation rate for uniform energy distribution. We are able to follow the desorption dynamics of particles' immediately after the first layers have been formed. These results are in close relation to the surface binding energy of the evaporated material and offer a better control to obtain the desired properties of the thin surface layer. The novelty of our work consists of the demonstration that quartz crystal μ-balance can be successfully implemented to monitor complex dynamics through the energy interaction of particles during PVD. We applied our technique to investigate the PVD mechanism for diverse elements, usually implemented in the development of film surface layers, such as Cu, W, Au, Gd and In, and confirm that our results are in agreement with measurements done previously with other techniques such as low temperature photo-luminescence.

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“…Commonly likened to the sublimation energy [44,45], it is possible to determine this quantity from atomistic simulations [45]. The SBE for the SW m potential used in our work is computed in a scheme similar to the one of Yang et al [46]. Considering the free surface of a perfect crystal at 0 K, a velocity parallel to the outward-pointing normal of this surface is prescribed to an atom, and a MD simulation is performed in the NVE ensemble for 2 ps.…”

Section: Calculation Of Threshold Displacement Energy and Surface Binmentioning

confidence: 99%

Atomistic simulations of focused ion beam machining of strained silicon

Guénolé

Prakash

Bitzek

2017

Applied Surface Science

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The focused ion beam (FIB) technique has established itself as an indispensable tool in the material science community, both to analyze samples and to prepare specimens by FIB milling. In combination with digital image correlation (DIC), FIB milling can, furthermore, be used to evaluate intrinsic stresses by monitoring the strain release during milling. The irradiation damage introduced by such milling, however, results in a change in the stress/strain state and elastic properties of the material; the change in the strain state in turn affects the bonding strength, and is hence expected to implicitly influence irradiation damage formation and sputtering. To elucidate this complex interplay between strain, irradiation damage and sputtering, we perform TRIM calculations and molecular dynamics simulations on silicon irradiated by Ga + ions, with a slab and trench-like geometry, whilst simultaneously applying uniaxial tensile and compressive strains up to 4%. In addition we calculate the threshold displacement energy (TDE) and the surface binding energy (SBE) for various strain states. The sputter rate and amount of damage produced in the MD simulations shows a clear influence of the strain state. The SBE shows no significant dependence on strain, but is strongly affected by surface reconstructions. The TDE shows a clear strain-dependence, which however, cannot explain the influence of strain on the extent of the induced irradiation damage or the sputter rate.

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Atomic scale calculations of tungsten surface binding energy and beryllium-induced tungsten sputtering

Cited by 37 publications

References 26 publications

Surface morphology in tungsten and RAFM steel exposed to helium plasma in PSI-2

Surface morphology in tungsten and RAFM steel exposed to helium plasma in PSI-2

Energy exchange between atoms with a quartz crystal μ-balance

Atomistic simulations of focused ion beam machining of strained silicon

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