Figure 2
From: Novel Unexpected Reconstructions of (100) and (111) Surfaces of NaCl: Theoretical Prediction
(a) Atomic structures of the predicted stable reconstructions of the (111) surface of NaCl: NaCl6-(1 × 1), NaCl-(1 × 1), Na3Cl2-(1 × 1), Na3Cl-(1 × 1), and Na4-(1 × 1). (b) Surface energy as a function of µCl. The region of µCl = −2.2 eV to −2.3 eV is shown enlarged in an inset. (c) Convex hull diagram, where solid circles indicate the thermodynamically stable surface phases; the colors of the circles correspond to the colors of the lines in (b). (d) Phase diagram of the (111) surface of NaCl. The dashed horizontal line corresponds to ultrahigh vacuum conditions (10−13 bar). Reference data on the experimental conditions of NaCl(111) growth on Si(100)-(2 × 1)36, Si(111)-(7 × 7)37, and GaAs(111)35 substrates are represented by the small circle, square, and triangle, respectively. The light green region in (b) indicates the conditions at which Na3Cl-(1 × 1) appears on the crystal shape according to the Wulff construction (in this case, it corresponds to γ(111)/γ(100) < \(\sqrt{3}\)).
