In-plane relaxation of Cu(111) and Al(111)/α-Al2O3 (0001) interfaces -: art. no. 033410

The electronic structure and total energy of the Al and Cu alumina interfaces have been calculated with the plane wave pseudopotential method based on Lanczos diagonalization of the Kohn-Sham density matrix. For both interfaces we found in-plane relaxation, resulting in the rotation of the O triangle and expansion of the O-O bonds at the alumina surface. The calculated adhesive energies of the Cu(111)/alumina and Al(111)/ alumina interfaces are several times smaller than that of the Nb(111)/alumina interface. The Cu(111)/Al-terminated alumina interface is found to have the smallest adhesive energy which is presumably related to the high degree of spatial delocalization of metal-oxygen bonds at the interface.