First-principles study of Zintl aluminide SrAl2

Zintl intermetallics hold promise for applications in oxide/semiconductor epitaxy. We report a density functional investigation of the Zintl phase strontium aluminide SrAl2. We calculate electronic properties of the orthorhombic and cubic phases. For the orthorhombic phase, we calculate the work function and surface energy for (001), (010), and (100) orientated surfaces. The work function varies between 2.0 eV and 4.1 eV, and it is determined by the predominant atomic species on the surface. The surface energy ranges from 320 erg/cm(2) to 1842 erg/cm(2). We also calculate the elastic constants.