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N是金刚石中的主要杂质之一,为了研究金刚石生长过程中杂质N对C电子结构转化的影响,用密度泛函理论研究了Ni(111)表面上C与N共吸附的三个不等价模型,同时建立了三个C吸附模型作为比较.计算结果表明,N原子的出现使得吸附体系相对不稳定,吸附原子之间的相互作用不能忽略;通过比较相互作用能可以看出,相同的吸附位下C-C相互作用比C-N相互作用强.通过比较不同模型中C原子分波态密度可以看出,N-C相互作用一定程度上增加了Ni的催化活性,但是与C-C自身的相互作用比较起来效果并不明显.吸附几何结构和分波态密度还表明,当吸附的原子过于紧密以致占有同一个Ni(111)-(1×1)晶胞表面时,就会形成CN化合物或者类石墨杂质.
N is one of the major impurities in diamond. In order to study the effect of impurity N on the electronic structure transformation of diamond during diamond growth, three inequalities of co-adsorption of C and N on Ni (111) surface were investigated by using density functional theory Model, at the same time, three C adsorption models were established for comparison. The calculation results show that the adsorption system is relatively unstable due to the presence of N atoms, and the interaction between the adsorbed atoms can not be ignored. By comparing the interaction energies, it can be seen that the same adsorption The CC interaction at the lower position is stronger than that at CN. Comparing the cesium subwavet density in different models, it can be seen that the NC interaction increases the catalytic activity of Ni to a certain degree, but the interaction with CC itself is more effective It is also evident that the adsorption geometry and the partial density of states also show that CN compounds or graphite-like impurities are formed when the adsorbed atoms are too close to occupy the same Ni (111) - (1 × 1) unit cell surface.