Order and Melting in Self-Assembled Alkanol Monolayers on Amorphous SiO2
Haddad, J; Steinrueck, HG; Hlaing, H; Kewalramani, S; Pontoni, D; Reichert, H; Murphy, BM; Festersen, S; Runge, B; Magnussen, OM; Magerl, A; Deutsch, M; Ocko, BM
| HERO ID | 4937186 |
|---|---|
| In Press | No |
| Year | 2015 |
| Title | Order and Melting in Self-Assembled Alkanol Monolayers on Amorphous SiO2 |
| Authors | Haddad, J; Steinrueck, HG; Hlaing, H; Kewalramani, S; Pontoni, D; Reichert, H; Murphy, BM; Festersen, S; Runge, B; Magnussen, OM; Magerl, A; Deutsch, M; Ocko, BM |
| Journal | Journal of Physical Chemistry C |
| Volume | 119 |
| Issue | 31 |
| Page Numbers | 17648-17654 |
| Abstract | Molecular self-assembly is a key to wide-ranging nano- and microscale applications in numerous fields. Understanding its underlying molecular level science is therefore of prime importance. This study resolves the angstrom-scale structure of the earliest and simplest self-assembled monolayer (SAM), octadecanol on amorphous-SiO2-terminated Si(001) substrate, and determines the structures temperature evolution. At low temperatures lateral hexagonal order exists, with close-packed, surface-normal molecules. At similar to 12 degrees C above the alkanols bulk melting, a fully reversible disordering transition occurs to a novel stretched liquid phase, laterally disordered, but only similar to 15% thinner SAM than in the crystalline phase. The SAM persists to >= 100 degrees C. A thermodynamic model yields here a headgroup-substrate bond energy similar to 40% lower than on crystalline sapphire, highlighting the importance of the substrates order, and near-epitaxy, for the SAMs ordering and stability. |
| Doi | 10.1021/acs.jpcc.5b03554 |
| Wosid | WOS:000359332200017 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |