STUDY OF SURFACE ENERGY AND WORK FUNCTION OF HEX METALS BY FIRST-PRINCIPLES CALCULATION

Abstract

Surface energy and work function are important for understanding metal surface performance. There have been many reports concerning these problems for bcc and fcc metals. However, for hex metals, there are few reports, especially for some surfaces with higher indices. This work focuses on the calculation of surface energies and work functions for Be, Mg, Ti and Zr. Many different surfaces with higher indices are calculated, including (0001), (02 (2) over bar1), (10 (1) over bar0), (12 (3) over bar1), (12 (3) over bar0) and (01 (1) over bar1). The results show that the surface energies and work functions have a strong relationship with each other. The work functions of these surfaces follow such sequence: Phi(0001)>Phi(02 (2) over bar1)>Phi(10 (1) over bar0)>Phi(12 (3) over bar1)>Phi(12 (3) over bar0)>Phi(01 (1) over bar1), corresponding their surface energies: gamma(0001) 1) 0) 1) 0) 1). What's more, the results also show that, for these metals in the same group, the small ones in atomic number such as Be and Ti, compared with Mg and Zr, have larger values of work functions and surface energies. In addition, the (0001) surface has the largest value of work function but smallest value of surface energy, which is in good agreement with experiment outcomes.