优质细颗粒金刚石单晶的高温高压合成与表征

Synthesis and characterizing of diamond single crystal with ultra-fine grain size under high pressure and high temperature

文章利用国产六面顶高温高压设备,根据对金刚石合成不同区域的生长特点,通过对合成工艺的调整,实现了对体系中金刚石成核率与生长速率的控制,并成功合成出了具有完整晶形,尺寸大约在2-10μm的优质细颗粒金刚石单晶。通过热重-差热分析以及Raman光谱测试发现,合成具备完整晶面的细粒度金刚石单晶抗氧化强度大于表面粗糙的同粒度的金刚石微粉破碎料,且合成的晶体内部存在较小的残余应力。

High-quality diamond single crystals with micron grain size are synthesized with a new high-pressure and high-temperature（HPHT） synthesis technique in a cubic hinge apparatus.Morphology of the synthesized diamonds is observed by a scanning electron microscope（SEM）.The samples are characterized using laser Raman spectra.The results show that the new synthesis technique improves the nucleation of diamond greatly,and diamond single crystals with perfect morphology and micron grain size are successfully synthesized,with the average grain size of about 2-10 μm.The TG-DTA results show that the synthetic diamond single crystals have higher thermal stability than that of the milled diamond.This work provides a new synthesis technique to implement industrialization of high-quality diamond single crystals with ultra-fine grain size,and paves the way for future development.