멀티스케일 시뮬레이션을 이용한 PbCu 및 ZnO 시스템의 자기정렬 특성 연구

Abstract

Pb heterostructure formation on Cu (111) substrate in early stage of deposition process and stress-induced phase transformation in ZnO nanowires were observed and investigated with self-assembling characteristic, which is essential in synthesis of nano-sized devices. Deposited Pb adatoms on Cu (111) substrate formed clusters through live diffusion. The Pb heptamer is most stable among the possible Pb nuclei. To investigate stability of Pb heptamer, the surface energy, the diffusion energy barrier, and the adsorption energy of Pb nuclei were calculated. Moreover, we observed stress-induced Wurtzite to Hexagonal phase transformation in ZnO nanowires with reactive force field potentials. Hexagonal ZnO nanowires turned out to be meta-stable phase at all temperature by calculation of stress-strain curve, atomic stress configuration, and average energy per atom. To observe atomically, all experiment was done by computer simulation. Atomic scale (molecular dynamics) and electronic scale (density functional theory) simulation were employed.