Stability of ultrathin Ag films on Ta(1 1 0)

The stability of ultrathin Ag films on Ta(1 1 0) has been studied by photoelectron spectroscopy. Strained films of 1 and 2 ML Ag/Ta(1 1 0) were found to be particularly stable for temperatures up to 900 K, while photoemission spectra measured on thicker films indicate a three-dimensional growth. Analysis of the observed quantum well states (QWS) within the phase accumulation model confirms the observed QWS positions while the evaluation of the total energy for the different film thicknesses does not reveal characteristic oscillations. These results indicate that the stability of the first 2 ML of these distorted Ag films is dominated by adsorbate–substrate bonding rather than electron confinement.