一维纳米材料中电子局域态分布
来源期刊：中南大学学报(自然科学版)2004年第3期
论文作者：徐慧 马松山
文章页码：363 - 367
关键词：纳米材料;电子局域态;局域中心;晶界无序度
Key words：nanometer materials; electronic localization; central position of localization; disorder degree of interfacial atoms
摘 要：从一维纳米随机链模型出发,在考虑近邻、次近邻相互作用的情况下,运用多对角全随机厄米矩阵求解方法计算了一维纳米材料的电子局域态中心位置。针对晶界无序度和晶粒大小,讨论了材料中的电子局域态分布。研究结果表明:局域态中心位置随能量的改变而改变,并且在不同的能量范围内局域态分布不同,在某些能量范围内,能量变化很小而局域位置变化很大,电子跳跃很容易发生,而在另一些能量范围内,能量变化很大但局域位置变化很小,电子跳跃难以发生,因而直接影响材料的导电、导热等性能;晶界无序度和晶粒大小对局域态分布影响 很大,当晶界无序度变小时,体系趋向有序,局域态位置随能量的变化呈一定程度的周期性;而当晶粒粒径变小时,晶界的作用增强,无序作用也相应增强,局域态增多,分布密度增大。
Abstract: The central position of electronic localization in one-dimensional nanometer materials is calculated by using one-dimensional random nanometer chain model and considering the second-neighbor interaction. Aiming at the crystalline grain size and the disorder degree of interfacial atoms, the distributions of electronic localiza-tion in one-dimensional nanometer materials is studied. The results show that the central position of electronic localization varies with the energy of eigenstates and the distribution of electronic localization is different in different range of energy. In some range of energy, when energy changes little the central position of electronic localization changes greatly. Then the electron can easily hops from one position to another and the hopping distance is large. In other range of energy, though energy changes much, there is almost no change in the central position of electronic localization, and the electron hopping from one localization to another is difficult. At the same time, the crystalline grain size and the disorder degree of interfacial atoms have great effect on the distribution of electronic localization.
基金信息：教育部高等学校博士点专项科研基金资助项目
