First-principles study on stability and electronic properties of W(001), W(110) and W(111) surfaces

Based on Density Functional Theory (DFT), using first-principles pseudopotential plane wave method, surface relaxation, surface energy and Density of states (DOS) of metal W on low index surfaces (001), (110) and (111) were calculated. The results showed that: the relaxation and surface energy were |Δ14(110)| < |Δ14(111)| < |Δ14(001)| and Esurf(110) < Esurf (111) < Esurf(001), respectively. The surface relaxation and surface energy of W(110) were both minimum, which proved that W(110) was the most stable surface. This result was in good agreement with experimental XRD pattern. According to Density of states, the essence of the distinct stability of W(001), W(110) and W(111) was discussed further.