FREQUENCY-DEPENDENCE OF THE DIELECTRIC-PROPERTIES IN MGO-LINBO3 CRYSTALS

MgO-doped congruent composition LiNbO3 crystals were grown by the Czoc hralski method. All MgO:LiNbO3 melts have a higher melting temperature than that of a pure one. Frequency dependence dielectric spectra were measured to study the relaxation and conduction mechanism of these cr ystals. Strong, low frequency dispersion indicated that the main condu ction of MgO-doped LiNbO3 is the hopping charge carrier which may be c aused by the defects or Mg-ions. Impedance spectra measurements show t hat this system does not satisfy a Debye but Jonscher's ''Universal La w''.