Fe-B-C体系金刚石单晶的高温高压制备与表征

Preparation and characterization of diamond single crystals in Fe-B-C system under high pressure and high temperature

在国产六面顶高温高压设备上,利用低价纯铁粉末为触媒开展含硼金刚石的制备研究。研究发现:无定型硼的掺入会导致金刚石合成条件(温度和压力)不断提高;晶体颜色由浅黄色逐渐变为黑色,晶体主要以八面体为主。利用扫描电镜(SEM)分析含硼金刚石的微观形貌,发现:硼添加后金刚石{111}晶面上存在微米尺寸的圆形凹坑。通过Raman光谱研究发现:随着硼掺入量的增加,金刚石特征峰发生蓝移,其半峰宽变大、晶体质量下降。通过红外光谱可以发现较强的Ⅱb型金刚石存在2800 cm-1处的B-C键特征峰。在纯铁触媒体系中,硼的质量分数在0.2%~0.8%时,均能合成出优质含硼金刚石。

High quality boron-doped diamond single crystal was synthesized by using low value pure iron powder as catalyst using a China-type cubic high-pressure apparatus.It is found that the synthetic conditions(temperature and pressure)of diamond increases with the increase of boron addition.The crystal color changes from light yellow to black,and the crystal is mainly in octahedral form.Scanning electron microscopy(SEM)is used to analyze the morphology of boron-doped diamond.It is found that there are round pits in micron size on the{111}crystal surface.According to Raman spectroscopy,the characteristic peak of diamond is blue shifted,and the crystal quality decreases with the increase of half peak width.The strong 2800 cm-1 B-C bond absorption peak ofⅡb-type diamond can be found by infrared spectrum.In the pure iron catalyst system,the suitable boron addition amount is 0.2%~0.8%,and the quality boron-doped diamond can be synthesized by optimizing preparation technology.