Analysis of impedance and electric modulus properties of sensing and transducing material lead zirconate titanate (PZT) ceramics doped with gadolinium

The sensing and transducing electroceramic material lead zirconate titanate (PZT) doped with the rare earth gadolinium (Gd³⁺) has been synthesized through solid-state reaction technique with chemical composition Pb_1-xGd_x(Zr_0.65Ti_0.35)_1-x/4O₃ where x = 0.00, 0.06 and 0.09. Electrical behaviour of the sintered samples has been analyzed using complex impedance spectroscopy (CIS). The real and imaginary parts of impedance have been investigated within wide range of temperatures and frequencies. The complex Z'~Z" Nyquist plots exhibit single semicircle or its tendency. It suggests about the presence of mostly bulk resistive (grain) contributions in the materials with a decreasing tendency as temperature increases. It shows negative temperature coefficient of resistance (NTCR) type behaviour of the materials. Complex modulus M'~M" plots indicate the presence of grain (bulk) as well as grain boundary contributions in the materials. It also supports the NTCR behaviour of the materials. Both the complex impedance and modulus plots indicate the presence of non-Debye type of relaxation in the materials.