Dielectric properties of e-gun evaporated LiNbO3 thin films

Lithium niobate, LiNbO₃, thin films are mostly known for their technological applications in electrochromic displays or in all solid state thin film microbatteries. Various methods have been used for preparation of LiNbO₃ thin films. Lithium niobate was prepared as a thin film layered structure using e-gun evaporation for this study. Metallic films of Li between two Li-Nb-O layers provided "Li doping" after some thermal treatment. The real and imaginary parts of the complex impedance, Z´ Z", were measured and the loss tangent was calculated from the measured values of Z´ and Z". Two different polarization processes were estimated from the acquired frequency dependencies of the loss tangent. An equivalent circuit, describing the behaviour of the samples, was proposed and the transport processes in the prepared samples are discussed.