First‐principles studies on structure stability, segregation, and work function of Mg doped with metal elements

Abstract

AbstractThe first‐principles methods based on the density functional theory were employed to study the structural stability, segregation and work function of Mg doped with 14 metal elements existing in human body. The calculated results show that there is a simple correlation between structural stability and segregation. Doping of Sn, Y, Li, Gd, Nd, Sc, and Zn atoms produce a negative formation energy as well as a positive segregation energy. This suggests that these elements easier to be dissolved in Mg matrix do not tend to segregate on the Mg (0001) surface. An opposite trend was observed for Ba, Fe, Mn, W, Sr, and Ca. On the other hand, the electronic work function of Mg (0001) surface was increased significantly when doping Mo, W, Fe, and Mn, and was reduced markedly for Ba, Ca, and Sr. For Li, Sn, Sc, Gd, and Y, the doping of these elements on Mg surface generates a relatively small change in work function. In addition, the relationships of corrosion behavior to segregation and work function were discussed. This study may provide an avenue for seeking a more appropriate alloying element of Mg alloys with improved corrosion resistance in biomedical applications.