MHz), connected to an external oscillator (MCVAC) and a read-out unit TFM260 (BeamTec). The crystals were used as received and were not polished prior to deposition. A higher surface area was consequently expected and confirmed by atomic force microscopy (AFM), showing a root mean square roughness of 290 nm on a 50 µm × 50 µm area. For that reason, we refer to the ∆𝑚/𝐴 term, in equation (1), as "mass evolution" in arbitrary units due to the uncertainty in crystal surface area. In our QCM calculations we still assume a perfectly flat surface. We are aware that surface roughness affects the absolute value of the areal mass density, although we want to stress that it does not affect the characteristics of the result, which ultimately allows us to establish qualitative trends.