面心立方晶格构成的材料其表面与体内原子数之比的一种计算  

An approach to calculate the ratio of numbers of surface atoms to interior atoms in a material consisting of face-centered cubic lattice

作　　者：李广[1] 吴明在[1] 王磊[1] 

机构地区：[1]安徽大学物理与材料科学学院,安徽合肥230601

出　　处：《大学物理》2014年第6期1-3,10,共4页College Physics

摘　　要：纳米材料因其较大的比表面积往往显示出不同于其块体材料的性质,尤其是倍受重视的金属纳米材料.组成金属单质材料的晶胞很多是面心立方晶格(密堆积排列的一种形式).为了更好地帮助初学者理解其比表面积的概念,需要找到一种估算金属纳米材料的表面原子数和体内原子数目之比的一种方法.设想金属颗粒材料由最小的面心立方晶胞沿3个轴向等量重复堆砌而成,通过推理,可以得到不同尺寸大小颗粒的表面原子数与体内原子数的递推公式,由此可以估算出这类材料尺寸小到什么程度时其比表面效应就会突显出来.Due to the well-known effect of large specific surface area of nano-materials, they tend to show distinct properties other than bulk materials at large scale, especially the nanoparticles of metals which have been paid much attention. Most of metals consist of face-centered cubic （one of close packing lattices） unit cells. In this pa- per, an approach to calculate the ratio of numbers of surface atoms to interior atoms in a bulk materials with face- centered cubic lattice is proposed. Supposing the metallic particles consists of repeated unit cells that are stacked e- qually in the three crystal axes directions, a recursion formula can be addressed on how to calculate the numbers of surface atoms to interior atoms of particles with different sizes. According to the method, the size of a certain material that shows considerable effect of specific surface area can be estimated.

关 键 词：金属纳米颗粒 面心立方晶格 比表面积 

分 类 号：O48[理学—固体物理]