Multiscale Design of Nanostructured Ceramics for High-frequency Electromagnetic Applications

用于高频电磁应用的纳米结构陶瓷的多尺度设计

基本信息

批准号：
17560597
负责人：
TSURUTA Kenji
金额：
$ 2.35万
依托单位：
Okayama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

项目摘要

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.

在这项研究中，我们为超高速大众通信设备中使用的纳米结构材料开发了新颖且高精度的模拟方法。我们应用这些方法阐明了缺陷、晶界和杂质对纳米结构陶瓷和半导体电子和磁性能的影响。在研究期间，我们获得了以下成果： 1．基于紧束缚近似，通过时变薛定谔方程计算了硅纳米线的电子输运系数；2．采用混合量子/经典分子动力学方法分析了杂质氢在Si晶体和晶界中的扩散过程。我们发现了缺陷与杂质相互作用导致H原子活化能在1000K左右及以上突然下降的可能机制。 3．我们发现当Ni杂质插入到间隙位置时，金刚石的残余磁化强度可能是局部产生的。 4．采用经典图谱法，通过低维系统中俘获电子之间的相关性来评价低维电子系统的自旋极化率。 5．通过结构分析和简正模态分析来研究熔化过程与振动模态之间的关系。 6．开发了超材料电磁响应的有限差分时域（FDTD）模拟方法，并将其应用于金属-绝缘体多层结构。我们在许多国内学会会议和四次特邀报告中介绍了这些结果。