Enhanced electrical surface conductivity of LiNbO3 induced by argon-ion bombardment

The surface conductivity of pure and proton exchanged LiNbO₃ was studied. After bombarding the surface with Ar⁺ ions having an energy of about 2000 eV the samples showed an enhanced specific conductivity near the surface (5 nm) of 6 orders of magnitude. This corresponds to a specific conductivity of 10^–5 S/cm at room temperature. The enhanced conductivity is thermally activated with an energy of 0.41±0.04 eV, and it seems to be a non-ionic conductivity, because no polarization behaviour was observed. This enhanced conductivity was observed at the surface of both pure and proton exchanged LiNbO₃.