Field-emission resonance measurements with mechanically controlled break junctions

Properties of oxide thin films and their adsorption behavior studied by scanning tunneling microscopy and conductance spectroscopy

“…The first level is hereby excluded, because its energy is strongly altered by image potential interactions that are not considered in the model. 269 In good agreement with the results of the dI/dV maps, the surface potential rises when going from the top domain (3.5 eV) to the fcc (3.65 eV) and hcp domain (3.85 eV), reflecting the increase of the interlayer distance predicted by the hard sphere model. Compatible information on the local surface potential is obtained from spatial variations of the effective barrier-height Φ eff that is experienced by electrons tunneling from the tip to the sample.…”

“…At this point, it is sufficient to note that the energy position of such resonances sensitively depends on the local work function, as this quantity sets the environment in which FER develop. 269,270 Probing the first FER state on a regular versus a defect position in the oxide surface therefore yields information on the work function difference between both regions.…”

“…3.25B). 269 The surface potential is explicitly included in the approach, as it sets the bottom of the potential and provides an offset to all FER levels.…”

“…269 The Φ value for all three domains is now deduced from fitting the experimental FER positions to the calculated ones. The first level is hereby excluded, because its energy is strongly altered by image potential interactions that are not considered in the model.…”

Electron trapping in misfit dislocations of MgO thin films

“…1͔: E n = + ͑ 3 បe·F 2 ͱ 2m ͒ 2/3 n 2/3 . 22 As FER carry most of the electron current at high bias, their availability above the MgO surface determines the image contrast in the STM. 16 Apparently, the defect lines offer no or fewer FER than the regular oxide patches and consequently appear dark ͓Fig.…”