【摘要】 作者将分子模拟技术应用于材料介电性能研究中,以了解介电常数随温度变化规律的问题,从而有效地分析相关的微观结构特性.首先利用分子动力学对微观结构模型进行恒温下的分子动力学计算,然后对于该动力学结构模型再进行第一性原理计算,得到该温度下能带结构和介电常数等.通过改变分子动力学设定的温度,得到不同温度下材料微观结构的变化情况以及介电常数随温度的变化规律.作者分析了二氧化硅晶体微观结构和介电常数之间的关系,得到费米能量、禁带宽度和晶胞体积成反比关系的规律,建立了二氧化硅晶体介电常数和温度之间的关系.更多还原

【Abstract】 Molecule simulation technique has introduced to research dielectric property in order to solve the difficulties in measuring dielectric property under different temperature and analyzed the relationship between microstructure and dielectric property. Firstly, 3D model of silicon dioxide was put in calculation of molecule dynamics simulation with a definitive temperature. Then constant temperature microstructure model of silicon dioxide has been obtained.Secondly, first-principles simulation has executed to computer this microstructure model. At last the dielectric property of silicon dioxide under this temperature was obtained. By changing temperature of simulation, we can study changes of dielectric property with temperature and analyze the microstructure changes related with dielectric property. In this paper, the relationship between different microscopic parameters for silicon dioxide was carried out. The authors found that Fermi energy and forbidden gap energy is inversely proportional to volume of cell. The law between dielectric constant and temperature was founded.更多还原