Symmetry breaking at surfaces holds the clues for electron filling
D. Pesquera, G. Herranz, A. Barla, E. Pellegrin, F. Bondino, E. Magnano, F. Sánchez , J. Fontcuberta
Nature Comm. 13 Nov. 2012, DOI: 10.1038/ncomms2189
Electron occupancy at atomic orbitals of metal ions in solids results from the crystalline field acting on the atoms. Strain acting on films allow to modify it. Here, we show that the disruptive contribution of surfaces makes an important role and ultimately determines the electron filling at orbitals at surfaces. The corresponding phisicochemical properties largey depend on this balance.