Phase transformations in a complete monolayer of 4,4′-biphenyl-dicarboxylic acid on Ag(0 0 1)

Controlled Kinetics of On-Surface Dehydrogenation using a Low-Energy Electron Beam

“…The sequence of LEED patterns presented in Figure 3b reveals that an e-beam with an energy lower than 10 eV first induces the formation of the intermediate  phase, 11 the structure of which is shown in Figure 3f. This is followed by further transformation to a molecular phase not observed in earlier works 11,43,44 (denoted as the  phase in the following). The structure of the  phase is shown in Figure 3g).…”

“…Therefore, the measurements of the e-beam effect on the sample independent of nucleation and growth would be highly desirable. Recently, we have shown 43 that the temperature-induced transformation of the BDA phase that form full layer on the Ag(001) surface fulfills this condition. For a full monolayer coverage, the phase transformation proceeds differently than for submonolayer coverages: instead of the  phase, the so-called α phase is formed.…”

“…The as-deposited  phase (Figure 2b,c; and the corresponding diffraction pattern shown in Figure 3a) comprises an ordered network of hydrogen-bonded BDA molecules on both Ag(001) 11,43,44 and Ag(111) substrates. The e-beam irradiation leads to the formation of new molecular phases.…”

“…For a full monolayer coverage, the phase transformation proceeds differently than for submonolayer coverages: instead of the  phase, the so-called α phase is formed. 43 The transformation to the α phase proceeds internally and features the formation of a carboxylatesubstrate bond, which requires only minor vertical and horizontal shifts of BDA within the existing structure. We found that similar transformation occurs within the BDA islands upon their e-beam irradiation.…”

“…The samples were prepared by the method described in refs. 11,43,44 . In brief, the experiments were performed in the UHV system at the CEITEC Nano Research Infrastructure.…”