中文摘要：

利用高温高压温度梯度法,在FeNi-C-FeS体系中进行了宝石级金刚石大单晶的合成研究,重点考察了FeS含量对金刚石中氮含量的影响。结果发现体系中随着掺杂FeS含量的增加,晶体品质会遭到一定程度的破坏,尤其是{100}生长区域。对晶体中氮含量而言,当掺杂FeS的量由0增加至1.25%时,{111}生长区域的氮含量与纯FeNi-C体系相比几乎没有发生变化,而{100}生长区域的氮含量却发生较大变化,远远低于纯FeNi-C体系中{100}生长区域的氮含量。这说明掺杂FeS更易对晶体的{100}生长区域产生影响,或者说S元素更容易进入{100}生长区域,这样S原子与N原子之间产生竞争,使氮原子进入金刚石的几率减少,导致{100}生长区域的氮含量急剧下降。

英文摘要：

Large gem diamond crystals were synthesized successfully in FeNi-C-FeS system by temperature gradient method（TGM） at high pressure and high temperature（HPHT）,and the effect of FeS on nitrogen concentration of diamond crystals was mainly investigated.It is found that,with FeS content inceasing in the system,the quality of crystals would be suffered a certain degree of damage,especially in the {100} growth region.As for nitrogen concentration in the crystals,when the content of FeS increases form 0.75% to 1.25%,the nitrogen concentration of the {111} growth region almost shows no change,compared to that in the pure FeNi-C system;however,the nitrogen concentration in the {100} growth region would be changed greatly,which is far lower than that of the FeNi-C system.This indicated that,with the introduction of FeS into the growth system,the {100} growth regions of diamond crystals would be easier to be damaged,or,S element is easier to be incorporated into the {100} growth region,so there exists a competition between the sulfur and nitrogen atoms,which makes the probability of nitrogen atoms incorporated into diamond crystals reduced greatly,and leads to the great decrease of the nitrogen contentration of the {100} growth region.