金刚石单晶/镍基金属包膜界面的相结构和形貌

PHASE STRUCTURES AND MORPHOLOGIES OF DIAMOND SINGLE CRYSTAL/ METAL FILM INTERFACE FORMED NiMnC SYSTEM

利用透射电镜和原子力显微镜(atomic force microscope,AFM)研究了高温高压合成金刚石过程中金刚石单晶/镍基金属包膜的界面结构和形貌。分析表明金刚石/金属包膜界面包膜一侧由Ni3C,Mn23C,γ(Ni,Mn)和纳米级金刚石颗粒组成,未发现石墨结构;金刚石晶面的AFM形貌与所对应的包膜表面形貌相近,但又不互为负形;金刚石(100)晶面为细小的颗粒状表面,而(111)晶面呈现出有台阶的平直表面。结果表明金刚石的生长不是源于石墨结构的直接转变。在高温高压下,金刚石/包膜界面至包膜熔体的温度梯度差异导致了金刚石晶面形貌的不同。

The phase structures and morphologies of diamond single crystal/metal film interface, formed from a Ni - Mn - C system, during the synthesis of diamonds under high temperature and high pressure （HPHT） were investigated by means of transmission electron microscope and atomic force microscope （AFM）. The phase composition analysis shows that the Ni3C, Mn2s C, γ-（Ni,Mn） and nano-scale diamond particles exist in the metal thin film contacting the diamond, and graphite was not found on the interface. AFM morphologies on diamond faces are similar to those of the corresponding film, but not embossing each other. The fine particles and terrace structures with homogeneous step height were found on the diamond （100） and （111） surfaces, respectively. The results indicate that the growth of diamond is not directly from the transition of the graphite structure. Under HTHP, the differences of the temperature gradients from diamond/film interface to the molten film result in the morphology differences between diamond crystal faces.