【摘要】 作为具有各种极端特性的金刚石材料的两种晶态,宏观大尺寸块体单晶金刚石和微观纳米单晶金刚石均因其优异的性能,引发了研究者们的持续关注。近些年来,两类金刚石的制备方法不断得到改进,其性能改善的技术层出不穷,更多的应用领域已被开发或处于探索之中。两种尺度的单晶金刚石在性能上各有千秋,同时二者之间具有千丝万缕的联系,两种晶态对应的晶粒尺度之间可以发生可控的互相转化。可以将块体单晶金刚石的合成过程描述为纳米晶的聚集、自组装和定向附着生长,从而从纳米晶转化为英寸级大单晶形态。反之,亦可以通过表面纳米化的方法将大尺寸单晶转化为纳米晶。本文介绍了两种不同尺度单晶金刚石的制备方法、性能和应用,对块体单晶和纳米晶之间的相互转化方式进行了重点阐述,并对这两种尺度的金刚石晶体的粒度调控等研究方向进行了说明和展望。通过晶态转化和粒度调控,可以实现生长过程中对产物形貌和粒度的设计,从而制备出新的结构或功能材料,同时促进晶体生长理论的完善。更多还原

【Abstract】 Diamonds with two extreme sizes, large single crystal and nanocrystalline, have completely different properties, and have aroused the continuous attention of researchers. Each has its own merits and can be converted into the other. The synthesis of large single crystal diamond can be described as the aggregation, assembly and combination of nanocrystalline nuclei, i.e., diamond transforming from the nano-scale to the inch scale. A large single crystal diamond can be transformed into nanocrystals by surface nanocrystallization. The preparation methods, properties and applications of single crystal diamonds of different sizes are introduced and the transformations between them are described. Research interest in controlling the crystal size is discussed.更多还原