Structural and electronic trends in the growth of Cu overlayers on the Nb(110) surface

The stages of growth of thin Cu overlayers (less than 3 monolayers) on the Nb(110) clean surface have been studied by low-energy electron diffraction (LEED), Auger-electron spectroscopy, and angle-resolved photoemission spectroscopy. The LEED spectra indicated that in the early stages of growth less than about 1.5 monolayers of Cu grows in an incommensurate structure resembling a strained fcc (100) Cu surface designated Cu(I). Above that coverage the overlayer transforms to a fcc Cu(111) surfacelike structure designated Cu(II). The spectral features observed in the Cu(I) and Cu(II) photoemission spectra are compared with those of Cu(100) and Cu(111) surfaces.