http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Nickel silicide에 대한 Pd 첨가 효과 : ab initio 계산
김대희,서화일,김영철,Kim, Dae-Hee,Seo, Hwa-Il,Kim, Yeong-Cheol 한국반도체디스플레이기술학회 2008 반도체디스플레이기술학회지 Vol.7 No.1
Effect of Pd addition on crystal structures of two nickel silicides, NiSi and $NiSi_2$, is investigated by using an ab initio calculation. A Pd atom substitutes a Ni and Si site, respectively, to evaluate the preferable site between them. Pd prefers Ni site to Si site in NiSi, while it prefers Si site to Ni site in $NiSi_2$. The calculated total energy also indicates that the Pd substitution to Si site stabilizes the $NiSi_2$ structure. This calculated data matches well with the experimental data obtained from Atom probe.
김영철,서화일,Kim, Yeong-Cheol,Seo, Hwa-Il 한국재료학회 2007 한국재료학회지 Vol.17 No.7
Cobalt subtitution on NiSi is investigated by using an ab-initio calculation. Firstly, a relaxed NiSi structure is calculated and the calculated lattice parameters are compared with experimentally determined lattice parameters. The calculated values are smaller than the experimental values by about 2%. As the calculation is based on 0 K, and the experimental measurement is performed at room temperature, those values are in good agreement. Next, a Co atom substitutes a Ni and Si site, respectively, to evaluate the preferable site between them. Co prefers Ni site to Si site. The calculated total energy also indicates that the Co substitution to Ni site stabilizes the NiSi structure. Therefore, the thermal stability of NiSi with Co addition can be achieved by the structure stabilization of NiSi by Co substitution into Ni site of NiSi.
NiSi와 $NiSi_2$에 대한 Co 치환의 영향: ab initio 계산
김영철,서화일,Kim, Yeong-Cheol,Seo, Hwa-Il 한국반도체디스플레이기술학회 2007 반도체디스플레이기술학회지 Vol.6 No.3
Effect of Co substitution on crystal structures of two nickel silicides, NiSi and $NiSi_2$, is investigated by using an ab initio calculation. Relaxed NiSi and $NiSi_2$ structures are calculated and the calculated lattice parameters are in good agreement with experimentally determined lattice parameters within about 2%. A Co atom substitutes a Ni and Si site, respectively, to evaluate the preferable site between them. Co prefers Ni site to Si site in both NiSi and $NiSi_2$. The calculated total energy also indicates that the Co substitution to Ni site stabilizes both the NiSi and $NiSi_2$ structures. Co also prefers Ni site in $NiSi_2$ to that in NiSi, indicating that $NiSi_2$ becomes more stable than NiSi with Co substitution. As Co addition to NiSi improves its thermal stability experimentally, this indicates that the energy barrier between the two phases is high enough to prevent the phase transformation from NiSi to $NiSi_2$ up to high temperature.
제 1원리 젠스 계산을 이용한 LiNi<sub>x</sub>Mn<sub>1-x</sub>O<sub>2</sub> 내에 전이금속 이동에 대한 연구
정은석 ( Eun-suk Jeong ),한상욱 ( Sang-wook Han ) 전북대학교 과학교육연구소 2017 과학과 과학교육 논문지 Vol.42 No.2
We have examined transition metal (TM) migration into Li layer during charging under LiNi<sub>x</sub>Mn<sub>1-x</sub>O<sub>2</sub> using ab-initio XANES calculation. Green function and self-consistent method implanted in FDMNES code were used to calculate XANES and density of states (DOS). To identify the migration to Li layer, the Li closest to a probed atom was replaced by TM. Ab-initio calculation reveals that the whiteline decreased and shifted to high energy via the migration of Mn ions, whereas the migration of Ni ions made the convergence unstable. The calculation of DOS showed that the peak of pre-edge is contributed by 3d-4p hybridization and the XANES is formed by the transition of electron into p-state. In this paper, we will demonstrate XANES and DOS in detail as TM migrates to Li layer.
Choe, Jong-In Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.2
Molecular structures were optimized for the 1,3-diethoxycalix[4]crown-5-ether (2) in the various isomers and their potassium-ion complexes by using B3LYP/6-31+G(d,p)//B1LYP/6-31G(d,p) method after ab initio RHF/6-31G calculation. The cone-shaped isomer of 2 with cr-binding mode has shown the strongest binding efficiency among the six different complexes attributed to seven electrostatic interactions between the potassium cation and the oxygen atoms of crown-5-ether and ethoxy groups of the host (2). The vibrational spectra of 2 and its K+-complexes were obtained by restricted Hartree-Fock (RHF) calculations with the 6-31G basis set. The characteristic vibrational frequencies of various C-O-C stretching and bending motions are analyzed.
최종인 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.2
Molecular structures were optimized for the 1,3-diethoxycalix[4]crown-5-ether (2) in the various isomers and their potassium-ion complexes by using B3LYP/6-31+G(d,p)//B1LYP/6-31G(d,p) method after ab initio RHF/6-31G calculation. The cone-shaped isomer of 2 with cr-binding mode has shown the strongest binding efficiency among the six different complexes attributed to seven electrostatic interactions between the potassium cation and the oxygen atoms of crown-5-ether and ethoxy groups of the host (2). The vibrational spectra of 2 and its K+-complexes were obtained by restricted Hartree-Fock (RHF) calculations with the 6-31G basis set. The characteristic vibrational frequencies of various C-O-C stretching and bending motions are analyzed.
Schlegel, H. Bernhard Korean Chemical Society 2003 Bulletin of the Korean Chemical Society Vol.24 No.6
In ab initio molecular dynamics, whenever information about the potential energy surface is needed for integrating the equations of motion, it is computed “on the fly” using electronic structure calculations. For Born-Oppenheimer methods, the electronic structure calculations are converged, whereas in the extended Lagrangian approach the electronic structure is propagated along with the nuclei. Some recent advances for both approaches are discussed.
Ab-Initio Studies of Electronic and Spectroscopic Properties of MgO, ZnO and CdO
A. Schleife,C. R¨odl,J. Furthmuller,F. Bechstedt,P. H. Jefferson,T. D. Veal,C. F. McConville,L. F. J. Piper,A. DeMasi,K. E. Smith,H. Losch,R. Goldhahn,C. Cobet,J. Zuniga-Perez,V. Munoz-Sanjose 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5
We present ab-initio calculations of excited-state properties within single-particle and two-particle approaches in comparison with corresponding experimental results. For the theoretical treatment of the electronic structure, we compute eigenvalues and eigenfunctions by using a spatially nonlocal exchange-correlation potential. From this starting point, quasiparticle energies within the fully frequency-dependent G0W0 approximation are obtained. By solving the Bethe-Salpeter equation, we evaluate optical properties, including the electron-hole attraction and the local-field effects. The results are compared with experimental spectra from soft X-ray emission, as well as from X-ray photoelectron spectroscopy or ellipsometry measurements. In more detail, we compute the valenceband densities of states, bound excitons, and the dielectric function. For the latter, we discuss both the absorption edge and higher critical points.
Ab-initio study of the effects of charging on the adsorption and diffusion of Au2 on MgO(100)
Park Jong Hwan,Yang Jeong Woo,Byun Min Gyo,Hwang Nong Moon,Park Jinwoo,유병덕 한국물리학회 2021 Current Applied Physics Vol.24 No.-
By using ab-initio calculations, the adsorption and diffusion properties of charged Au dimers (Au+2 and Au 2 ) on MgO(100) were investigated and compared with those of the charge-neutral dimer (Au02 ). The most favored adsorption structure of Au+2 on MgO(100) is the upright dimer on a surface O atom in agreement with that of Au02 . The surface diffusion of Au+2 on MgO(100) occurs by the leapfrog process with a barrier height of 0.38 eV lower than that of Au0 2 (0.66 eV). The most stable adsorption structure of Au 2 on MgO(100) is the flat-lying dimer on two surface Mg atoms. The surface diffusion of Au 2 on MgO(100) can proceed by the hopping and walking processes with a barrier height in the range of 0.05–0.11 eV, which is much lower than the diffusion barriers of Au+2 and Au02 . Furthermore, detailed information on the electronic properties of Au02 , Au+2 , and Au 2 are also presented.
Ab-initio Study of Pressure Effects and Hydrogen Impurity in HgO
Minseok Choi,Chul-Hong Park 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.12
Through ab-initio pseudopotential calculations, we investigated the deformation potential of HgO semiconductors and the structural stabilities of various crystal structures under pressure. We also investigated the microscopic structure of the hydrogen (H) impurity in HgO. Especially the state of hydrogen atoms captured by an acceptor-like Hg-vacancy (VHg) is focused on. The location of H is found to be very different from the original Hg-site, forming a strong H-O bond. The capture two H atoms by VHg is found to be energetically favorable: the binding energy for one H and the second H are 1.01 eV and 0.07 eV, respectively.