Influence of alloying elements on the stability and segregation behavior of fcc-Fe/NbN interface by simulation.

In this effort, the influence of alloying element doping on fcc-Fe (111)/NbN (111) interface property is investigated by means of first principles. The interface structure combined with 5-layer fcc-Fe and 7-layer NbN is selected for investigation, because they exhibit characteristic consistent with the bulk counterpart. By calculating the interface energy, separation work and phonon spectra, the results show that interface 6 is stable. The alloying elements are more easily segregated at position 2 in the interface and it is chosen as the object of study. After Co and V doping, the separation work of the interface increases and the interfacial energy decreases. The degree of charge density consumption around them is greater than that of the intrinsic interface, indicating that the covalent bonds between atoms have been enhanced. This indicates that doping with Co and V atoms can improve the stability of the interface, which is consistent with the results towards population analysis and density of states. On the contrary, after doping with Zr, Sc, Y, and Ti atoms, the interatomic covalence weakens and the interface stability decreases. Especially for Y doping, the lowest electron consumption and the smallest electron cloud enrichment in the middle layer can be observed, demonstrating the worst interface stability. This insight has important guiding significance for the interface segregation behavior of alloying elements, and provides a theoretical basis for the development of next generation austenitic stainless steel. • Studied the effect of segregation of alloying elements Ti, Co, Zr, Y, V, Sc on fcc-Fe (111)/NbN (111). • After doping with Co and V atoms, the covalence between atoms is enhanced. • After doping with Co and V atoms, the interface stability can be improved. [ABSTRACT FROM AUTHOR]