Investigation of the structural and dynamical properties of the (0Â 0Â 1) surface of LiCu2O2

We report on studies of the structure and dynamics of the (0 0 1) surface of single crystal LiCu2O2, investigated by He beam scattering at room temperature, and with lattice-dynamical models. The best fit surface corrugation to measured diffraction patterns shows that the surface termination is exclusively a Li1+Cu2+O2− plane. Lattice dynamics fits to inelastic He scattering spectra reveal the presence of two low-lying surface phonon modes, identified with the motion of Cu2+, Li1+ surface ions normal to the surface.