Equilibrium alloy properties by direct simulation: Oscillatory segregation at the Si-Ge(100) 2×1 surface

We study surface and bulk equilibrium in Si-Ge alloys by direct simulation. The composition at a reconstructed (100) surface varies with depth in a complex oscillatory way. Lateral ordering occurs even in the fourth layer, driven by the local stress field. The bulk phase diagram is well described by regular solution theory. © 1989 The American Physical Society.