Multiscale Design of Nanostructured Ceramics for High-frequency Electromagnetic Applications

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In this research, we have developed novel and highly accurate simulation methodologies for nanostructured materials that are used in ultra high-speed mass communication devices. We have applied the methods to clarify the effects of defects, grain boundaries, and impurities on electronic and magnetic properties of nanostructured ceramics and semiconductors.During the research term, we have obtained the following outcomes:1. The electronic transportation coefficient in Si nanowires has been calculated via the time-dependent Schrodinger equation based on the tight-binding approximation;2. The diffusion processes of the impurity hydrogen in a Si crystal and grain boundary were analyzed by hybrid quantum/classics molecular dynamics method. We have found possible mechanism of the sudden drop of activation energy of H atom around and above 1000K due to the interactions between the defects and the impurity.3. We have found the possibility that the residual magnetization of diamond is locally generated when Ni impurities were inserted at interstitial sites.4. The spin polarizability in low-dimensional electron system was evaluated through the correlations between electrons trapped in low-dimensional system by the classics map method.5. The structural and normal-mode analyses were performed to investigate the relationship between melting processes and the vibrational modes.6. The finite-difference time-domain (FDTD) simulation methodologies for electromagnetic responses of meta-materials were developed and applied to the metal-insulator multilayer structures.We have presented these results in a lot of domestic societies meetings and in four invited lectures.