Polar Oxides
Polar Oxides
- Polar MgO(111)
- Self-assembled gold atoms on FeO
Polar Oxides
- Lattice structures with uncompensated charge distribution in the unit cell develop macroscopic dipole moment at the surface
- Dipole compensation by reconstruction, metallization or adsorption of charged species onto the surface
- Uncompensated surface polarity give rise to unusual physical and chemical phenomena (band bending, work-function changes, enhanced binding of adsorbates)
Polar MgO on Au(111)
- MgO(111) develops polar structure with reduced distance between Mg2+-/O2- -planes with respect to the bulk
- Formation of quasi metallic edge states at rims of the polar islands
For details: N. Nilius et al., Phys. Rev. B 86 (2012) 205410.
Self-assembly of Au atoms on polar FeO/Pt(111)
- Variable registry at FeO-Pt interface alters Feδ+-/Oδ- bond length and thus local dipole moments in the film
- Preferred Au binding to regions with high dipole strength triggers self-assembly into hexagonal atom pattern
For details: N. Nilius et al., Phys. Rev. Lett. 95 (2005) 066101.