It was noted that LiNbO3 thin films, deposited by electron-gun evaporation,
exhibited a lithium deficiency which could be cured by Li-doping. The Li doping
of the films was achieved by preparing a structure of Li-Nb-O/Li/Li-Nb-O, which,
after annealing, formed an homogenized LiNbO3 layer because of the diffusion of
Li into the two Li-Nb-O layers. The LiCoO2/LiNbO3 bi-layers were prepared either
on stainless-steel/TiN or on Al2O3/Co/Pt substrates/ohmic-contacts by depositing
either first the cathode, LiCoO2, or the electrolyte, LiNbO3. The Nyquist plots of
the AC impedance measurements of all of the structures showed that the interfaces
prepared onto stainless-steel/TiN consisted of two semicircles. The structures
deposited onto Al2O3/Co/Pt exhibited a third semicircle, which was probably due to
the roughness of the substrate. It was important that the ionic properties of the bilayers
with the cathode material deposited first were improved, compared to the
other structures. The quality of the LiNbO3 layer depended very much upon the
substrate. It could be deduced from Arrhenius plots that the activation energy of
this layer was considerably lower when the whole structure was deposited onto
stainless-steel/TiN.
Influence of Different Substrates on the Ionic Conduction in LiCoO2/LiNbO3 Thin-
Film Bi-Layers. E.E.Horopanitis, G.Perentzis, L.Papadimitriou: Physica Status
Solidi C, 2008, 5[12], 3763-6