It is indispensable to understand the adhesion strength between the film and the substrate for evaluating the film integrity. In case of calculating the adhesion strength numerically, ab-initio ...molecular dynamics based on quantum mechanics is necessary. In this paper, in order to solve fundamental process of the nucleation of the diamond based on quantum mechanics, ab-initio molecular dynamics simulation of the nucleation of the diamond on the silicon substrate is conducted. Only one carbon atom is used for the simulation because fundamental process of the nucleation is requested to be shown. Two types of the silicon substrate, one consists of perfect crystal and the other has a point defect, are used for the simulation and compared each other. Car-Parrinello method is used for ab-initio molecular dynamics calculation. The action of the carbon atom in the simulation, and the situation of the combination between atoms are shown.
NDE of a Crack by Local Heating with Laser Beam SAKA, Masumi; MATSUMOTO, Masanori
Transactions of the Japan Society of Mechanical Engineers Series A,
1998, Volume:
64, Issue:
627
Journal Article
Open access
A method was investigated for nondestructive evaluation of 2-D crack or slit depth by measurement of temperature difference between two points on the material surface in non contact. In the first, ...experiment was performed on the specimens of 304 stainless steel with a slit. Local temperature field around the crack or slit was formed by heating small area near the crack or slit with Nd : YAG laser beam, and temperature at a point was measured by infrared thermography. The slit depth was evaluated exactly by comparing experimental results with numerical analysis of non-steady heat conduction problem. Next similar experiment was carried out to evaluate the fatigue crack depth. However it was difficult to evaluate crack depth. because formed temperature field hardly changed either existence of the crack or not. So the effect of crack opening displacement on the temperature field was examined. It is shown that evaluating crack depth is possible by the present method, provided that load is applied to open the crack.
Ternary TlMeX2 compounds for MEMS application Lyskouski, Viachaslau; Nelayev, Vladislav
2010 Proceedings of VIth International Conference on Perspective Technologies and Methods in MEMS Design,
2010-April
Conference Proceeding
Results of ab initio simulation of electronic and magnetic properties of TlMeX 2 compounds (Me=Ga, In. Tl; X=S, Se, Te) under the of strain deformation influence are presented. It was confirmed ...theoretically the experimental data about prominent anisotropy of various physical properties of these compounds, i.e. about perspective of investigated nano-structured objects as a materials for using in various nano-devices, in particular, in sensor and micro-electro-mechanical systems.
Ab initio calculations are used to study the reduction of the work functions of tungsten (W) surfaces with one monolayer of adsorbed barium (Ba) and lithium atoms. We have carefully and ...systematically test the convergence of density-functional-theory (DFT) calculations in the local-density approximation or generalized-gradient approximation with a plane-wave basis set and ultra-soft pseudopotentials or the projector-augmented wave method as implemented in Vienna ab-initio simulation package. The DFT calculation shows that the work function of the Ba adsorbed onto a p(2times2) W(001) substrate is dramatically lowered by about 2.2 eV, provided that the fourfold hollow sites are occupied. With this approach, one can investigate more complex adsorbates onto the cathode surface of different materials.
Work function is one of the most fundamental electronic properties of a metallic surface. The calculations of work function in our work were performed using density-functional-theory (DFT) in the ...local density approximation, with a plane wave basis set and the projector-augmented wave method, as implemented in the Vienna ab-initio simulation package. Using DFT calculations, we investigated the work function of the tungsten substrate could be lowered obviously due to the adsorbed variant coverage and geometry of atoms on the tungsten (001) surface.
Work function is one of the most fundamental electronic properties of a metallic surface. The calculation of work function in our work were performed using density functional theory in the local ...density approximation, with a plane wave basis set and ultra-soft pseudopotentials or the projector-augmented wave method, as implemented in the Vienna ab-initio simulation package. We put another two tungsten layers and 1 or 2 atomic layers of barium on the bulk in sequence. A preliminary ab initio calculation shows that the work function of the tungsten substrate could be lowered obviously due to the adsorbed atoms distributed onto a W(001) surface.
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