【摘要】 对于高温高压温度梯度法合成金刚石来说,在触媒中添加除氮剂(Ti、Al等),可以合成无色的IIa型宝石级金刚石。实验使用国产六面顶压机和NiMnCo溶媒通过温度梯度法来合成Ⅱa型宝石级金刚石,主要研究了除氮剂铝对生长Ⅱa型宝石级金剐石的影响。由于铝的添加使得合成出的金钢石出现熔坑,并带有颜色等现象。大量实验表明:氮化铝的分解和过量铝的掺入是颜色和熔坑产生的原因。实验通过在约1210℃的低温区生长、降低生长速度至0．41mg／h,使金刚石的颜色和熔坑问题有了明显的改善。所以在用Al做除氮剂生长Ⅱa型宝石级金刚石时,为获得优质单晶,应以较低的生长速度在低温区生长晶体。更多还原

【Abstract】 In the process of synthesizing gem diamond by HPHT temperature gradient method ( TGM) , when nitrogen getter such as Ti and Al is added to the catalyst, colorless type II a gem diamond can be obtained. In this paper, type II a gem diamonds were synthesized in a cubic press using NiMnCo alloy as catalyst (solvent). The effect of the nitrogen getter-Al on the growth of type II a gem diamond was researched. The phenomena of cavities and light yellow color were observed in the synthesized diamond. A lot of experiments show that the decomposition of AIN and the excess additive Al are the reasons for the presenting of yellow color and cavities. The problems of color and cavities were solved by growing diamonds at low temperature ( about 1210℃ ) and at low growth rate (0. 41mg/h). Based on the above research results, it is suggested that when growing high quality diamonds using Al as nitrogen getter, lower temperature and at lower growth rate should be adopted.更多还原