Islands and holes as measures of mass balance in growth of the(3×3)R30°phase of Ag on Si(111)

Abstract

It is well known that conversion of Si(111)-(7×7) into the (√3×√3)R30° phase of adsorbed Ag requires a change in the Si density, and causes formation of islands and holes at the surface. By mass balance, the ratio of areas of islands and holes (R IH) should be approximately 1. However, we find that the ratio is significantly higher, depending on preparation conditions. A possible explanation would be that there are different types of (√3×√3)R30° structures. However, neither scanning tunneling microscopy nor density-functional theory (implemented as a genetic algorithm search) supports this explanation. We propose that the edges of the islands contain excess Ag which becomes available to expand the holes, when the island perimeter decreases. Under certain conditions, excess Ag is also made available by dissolution of small islands that are Ag rich.

Structural and Chemical Evolution of l-Cysteine Nanofilm on Si(111)-√3×√3-Ag: From Preferential Growth at Step Edges and Antiphase Boundaries at Room Temperature to Adsorbate-Mediated Metal Cluster Formation at Elevated Temperature

“…5,78 The step edges could appear either curved or straight with sharp angles depending on the surface preparation procedure. 79 The antiphase boundaries appear as straight bright lines in the STM image (Figure 3a1). The width of a typical antiphase boundary is 0.75 nm.…”

“…Each unit cell contains three Ag atoms and three underlying Si atoms (appropriately arranged as illustrated in area A2, Figure a3). The step edge appears in the [1−21] and [110] directions, and the height of the step (or the rise) is 0.31 nm. , The step edges could appear either curved or straight with sharp angles depending on the surface preparation procedure . The antiphase boundaries appear as straight bright lines in the STM image (Figure a1).…”

Ag on Si(111) from basic science to application

“…As shown in work by lass 6 , the surface phases of Au on Si often coe ist as one phase transitions to another. Over time particular attention was given to the (5 x 2) [65][66][67][68][69][70][71][72][73][74][75][76] and the -R ° 18, 2 , 58, 61, 6 , 65, 77-84 surface reconstructions. There is much similarity in the referenced work on the structure of these phases, but no single standard for either (5 x 2) or the -R ° structure has been established.…”

Creating nanoscale Ag patterns on the Si(111)–(√3 × √3)R30°-Ag surface via guided self-assembly

“…[11][12][13][14][15][16][17][18][19] The following facts are most germane to the present investigation. [11][12][13][14][15][16][17][18][19] The following facts are most germane to the present investigation.…”