Effect of Chrome (Cr) on the Electrical Properties in the PZT System Modified with Strontium and Chrome

Abstract

In all ferroelectrics, used as capacitor or transducer, the control of the conductivity is very necessary to improve the physical properties, because these compounds are used in industrial application and, thus, knowledge about this parameter is particularly important. In dielectrics, in general, the electrical conductivity increase with increasing temperature. It should be emphasized that in ferroelectrics there is also a maximum at the phase transition temperature Tc (critical point), where Tc is the temperature at which permittivity is at its maximum value. In the present paper the electric parameters of modified PZT Pb_0.95Sr_0.05(Zr_0.53Ti_0.47) + x%wtCr₂O₃ , x = 0.1, 0.2, 0.4, 0.5, near the morphotropic boundary zone, is studied and it is shown that the ferroelectric paraelectric transition temperature can be determined using ac measurements. The variation of the conductivity as a function of the temperature and frequency was studied. In all samples, the total conductivity σ (ω) as a function of frequency, exhibits a power law dependence (σ=σ_o+Aω^s , Jonscher universal response).