On the dielectric spectroscopy of copper doped layered Na1.6K0.4Ti3O7 ceramics

The copper doped derivatives of layered Na1.6K0.4Ti3O7 (SPT-3) ceramics have been investigated through dielectric spectroscopy in this work. The results indicate that the dielectric losses in these ceramics are the collective contribution of electric conduction, dipole orientation and space charge polarization. Smeared peaks in temperature dependence of permittivity plots suggest diffuse nature of high temperature ferroelectric phase transition. The light copper doping in SPT-3 enhances the relative permittivity. However, copper doping decreases dielectric loss due to inhibition of domain wall motion, enhances electron hopping conduction, and impedes the interlayer ionic conduction as well. Copper doping also gives rise to contraction of interlayer space.