温度对Ⅰb型和Ⅱa型金刚石大单晶(100)表面特征的影响  

Effect of temperature on the(100) surface features of type Ⅰb and type Ⅱa large single crystal diamonds

作　　者：张贺[1] 李尚升[1] 宿太超[1] 胡美华[1] 周佑默[1] 樊浩天[1] 龚春生[1] 贾晓鹏[2] 马红安[2] 肖宏宇[3] 

机构地区：[1]河南理工大学材料科学与工程学院、环境友好型无机材料河南省高校重点实验室培育基地,焦作454000 [2]吉林大学超硬材料国家重点实验室,长春130022 [3]洛阳理工学院数学与物理教学部,洛阳471023

出　　处：《物理学报》2015年第19期334-340,共7页Acta Physica Sinica

基　　金：吉林大学超硬材料国家重点实验室开放课题(批准号:201203);河南省教育厅重点资助(批准号:12A430010,13A140792);河南省高等学校矿业工程材料重点学科开放实验室开放基金(批准号:KLMEM2014-15);河南理工大学创新型科研团队支持计划(批准号:T2013-4)资助的课题~~

摘　　要：本文在5.6 GPa,1250—1340?C的条件下,利用温度梯度法,以FeNiMnCo合金为触媒,沿籽晶的(100)晶面成功合成了不同晶形的优质Ⅰb型和Ⅱa型金刚石大单晶.利用激光拉曼附件显微镜,分别对上述不同温度下合成的两类金刚石样品上表面(100)面的中心区域及棱角区域进行观察分析.研究发现,Ⅰb型和Ⅱa型金刚石大单晶(100)晶面上从中心到棱角处黑色纹路的分布逐渐变黑变密集;另外,随着金刚石合成温度的升高,Ⅰb型金刚石大单晶(100)面上黑色纹路由稀疏逐渐变稠密,而Ⅱa型金刚石大单晶的黑色纹路较为稀疏;Ⅰb型金刚石大单晶的形貌特征表现为从低温晶体的不规则分布过渡到中温、高温晶体的典型树枝状分布.Ⅱa型金刚石大单晶(100)面特征随温度变化规律与Ⅰb型的类似.这两类金刚石大单晶表面特征的差异可能是由于Ⅱa型金刚石具有比Ⅰb型更小的生长速度和更少的氮含量.最后,对两类塔状金刚石大单晶进行拉曼光谱测试分析,结果表明Ⅱa型金刚石大单晶的品质较Ⅰb型金刚石大单晶好.In this paper, by choosing FeNiMnCo alloy as a catalyst and the （100） face of a seed crystal as the growth face, high quality type Ib and type IIa large diamond single crystals （diameter about 3–4 mm） can be successfully synthesized using temperature gradient method, at 5.6 GPa pressure and different temperatures between 1250–1340 ℃. To control the diamond crystal morphology, the growth temperature should be adjusted. Then the morphology of the synthesized large diamonds is plate-like at low temperatures, tower-like at medium temperatures, and spire tower-like at high temperatures. For the same crystal morphology, the synthetic temperature of type IIa diamond single crystals is about 30 ℃ higher than that of type Ib. The central and angularity regions of the top （100） surface, for the synthesized samples of type Ib and type IIa large diamond single crystals at different temperatures, are examined by laser Raman microscope respectively. It is found that the black lines of the type Ib and type IIa large diamond single crystals become dimmed and dense on the same top surface from center to the edge. It is indicated that the priority growth mechanism is in the angularity regions, compared with the central regions. Namely the solute of carbon is primarily precipitated in the angularity regions of the （100） surface. With increasing synthesis temperature, the black lines on the top surface （100） of type Ib diamond single crystals become gradually denser, and the characteristics of the lines are transformed from irregular distribution to typical dendritic distribution. The reason of the above results is that the rate of carbon deposition （the growth rate of diamond crystal）, which is along the direction of the diamond crystal [100], will gradually rise as the synthesis temperature of the crystal is increased. The characteristics of the lines on the top surfaces （100） of type IIa large diamond single crystals, which are synthesized under different temperatures, are similar to that of ty

关 键 词：金刚石大单晶 温度梯度法 拉曼光谱 晶体生长规律 

分 类 号：O74[理学—晶体学] O613.71