添加不同硼源时金刚石的高温高压合成

Synthesis of Diamond Doping with Different Boron Sources under High Pressure and High Temperature

在压力6.5 GPa、温度1290~1350℃实验条件下,研究了合成体系中分别添加单质硼、六角氮化硼(h-BN)时金刚石的合成。由于合成体系中添加剂的存在,导致所合成的金刚石颜色发生了明显的改变。傅里叶显微红外光谱(FTIR)测试表明,当合成体系中h-BN添加量较少时,所合成金刚石中含有替代式的氮杂质,且金刚石中有sp2杂化的硼-氮、硼-氮-硼结构存在。当合成体系中h-BN添加量达到2wt%时,金刚石中的氮仅以硼-氮-硼的结构存在。此外,霍尔效应测试结果表明,硼掺杂金刚石具有p型半导体特性,而合成体系中添加h-BN所制备的金刚石表现为绝缘体。

The synthesis of diamond was respectively studied at pressure of 6.5 GPa and temperature ranging from 1290℃to 1350℃with boron and h-BN additives by temperature gradient growth method.The color of the synthesized diamond changed obviously,due to the existence of additives in the synthesis system.FTIR measurements show that the N impurity located in diamond in the forms of substitutional N,sp 2 B-N and B-N-B when the additive content of h-BN was small.However,N impurity existed in the diamond only in the form of B-N-B structure when the additive content of h-BN reached 2wt%.Additionally,Hall effects results showed that the obtained diamond with B additive exhibited p type semiconductor.However,the synthesized crystal with h-BN additive presented as an insulator.