Structural relaxation of adlayers in the presence of adsorbate-induced reconstruction:C60/Cu(111)

Self-assembly and ordering of C60 on the WO2/W(110) surface

“…The parallel orientation of the C 60 on the WO 2 /W(110) surface indicates that the moleculesubstrate interaction is strong enough to align the molecules at low temperature, when their movement is suppressed. Similar parallel orientation of the C 60 molecules has been previously observed on certain other surfaces by low-temperature STM [25,26,28,32,33]. It is noted that STM images exhibiting three molecular lobes within an individual C 60 molecule have been acquired at a sample bias in the range from +0.7 V to +1.0 V (+0.9 V in Fig.…”

“…The same value of corrugation was observed for oxide nanorows forming the WO 2 /W(110) surface [50], indicating that such an apparent height difference between C 60 molecules is due to the substrate topography. Furthermore, the similar apparent height difference (in the range 0.4-1.0 Å) has been observed between the 'bright' and 'dim' C 60 molecules on other surfaces and was explained by an adsorbate-induced reconstruction of the substrate [22,28,[32][33][34]. However, there is also a possibility of a slightly different interaction between the WO 2 /W(110) surface and the electron orbitals of the 'dim' C 60 molecules, caused by their specific arrangement on the surface, which results in proximity of the molecule to the W layer.…”

“…3a), which can be a reflection of local electronic and/or topographic variations. These so called 'bright' and 'dim' molecules have been previously observed by STM on a variety of surfaces and attributed to C 60 -induced substrate reconstructions [22,28,[30][31][32][33][34][35][36]. Such surface reconstructions can lead to two topographically different C 60 adsorption sites, where 'dim' C 60 molecules are sunk into nanopits of the reconstructed substrate, and are lower in height than 'bright' ones.…”

“…On most surfaces fullerene molecules self-assemble into close-packed monolayers with a hexagonal or quasi-hexagonal structure and a moleculemolecule separation close to 1 nm, as observed in bulk C 60 [18, 21-25, 27-38, 41]. In some cases the formation of a C 60 monolayer leads to an adsorbate-induced reconstruction of the substrate [22,28,[30][31][32][33][34][35][36]. Surprisingly, only few studies of C 60 on metal oxide surfaces have been performed to this end [42][43][44].…”

“…STM is a highly local technique that has become a powerful tool for studying the adsorption geometry and the conformation and dynamics of single organic molecules and molecular assemblies on conducting substrates [1][2][3][4][5][6][7][8][9][10]. Over the last decade STM has been used intensively for the study of C 60 self-assembled layers on a variety of metal [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] and semiconductor [18,[37][38][39][40][41] surfaces. On most surfaces fullerene molecules self-assemble into close-packed monolayers with a hexagonal or quasi-hexagonal structure and a moleculemolecule separation close to 1 nm, as observed in bulk C 60 [18, 21-25, 27-38, 41].…”