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采用基于密度泛函理论的第一性原理方法,对未掺杂Cr_2N及掺杂过渡金属W、Mo、Nb、Fe、Ni于Cr_2N超晶胞形成的Cr_(23)MN_(12)(M=W,Mo,Nb,Fe,Ni)的结构稳定性及电子特性进行研究。从形成热和结合能来看,W、Mo、Nb、Fe和Ni替换Cr掺杂到Cr_2N超晶胞中均可形成稳定结构Cr_(23)MN_(12)(M=W,Mo,Nb,Fe,Ni)复合氮化物。在所有掺杂元素中,Nb最容易掺杂于Cr_2N中形成Cr_(23)NbN_(12)复合氮化物,而W、Mo掺杂后形成的Cr_(23)WN_(12)、Cr_(23)MoN_(12)具有更高的稳定性,这是W-5d、Mo-4d和N-2p轨道耦合产生的影响。Fe、Ni掺杂后形成的Cr_(23)FeN_(12)和Cr_(23)NiN_(12)复合氮化物稳定性降低,主要是由于N原子中电荷转移给了Fe、Ni,而使得Cr_(23)FeN_(12)和Cr_(23)NiN_(12)复合氮化物电化学活性增强。
The first - principle method based on density functional theory (DFT) was used to study the Cr_ (23) MN_ (12) (M = W, Mo, Nb, Fe, Ni) structure stability and electronic properties were studied. From the formation of heat and the binding energy, Cr, Mo, Nb, Fe and Ni can be replaced by Cr into Cr_2N supercell to form a stable structure Cr 23 MN 12 (M = W, Mo, Nb, Fe, Ni) composite nitride. Among all the doping elements, Nb is most easily doped into Cr 2 N to form Cr 23 NbN 12 composite nitrides. However, Cr 23 WN 12, Cr 23, MoN_ (12) has higher stability, which is the effect of W-5d, Mo-4d and N-2p orbital coupling. The stability of composite Cr_ (23) FeN_ (12) and Cr_ (23) NiN_ (12) formed after Fe and Ni doping is decreased, mainly due to the charge transfer from N atom to Fe and Ni, 23) Electrochemical activity of FeN_ (12) and Cr_ (23) NiN_ (12) complex nitrides is enhanced.