Synthesis, characterization and properties of PZT materials modified with Nd PART II: Calcination, sintering of PNZT powders, and measurement of dielectric, dielectric, piezoelectric and ferroelectric properties.

Ceramic materials based on the quaternary system (Pb,Nd)(Zr,Ti)O-2 formed b y the substitution of Pb2+ by Nd3+ in PZT, (named PNZT) have been prepared and characterized physically, structurally and microstructurally. The quant ity of neodymium used ranges from 6-10% in moles and the Zr/Ti ratio in eac h of the prepared ceramics was 1.58/1, 3/1, 0.75/1 and 0.75/1 in moles. The precursor powders have been prepared by the sol-gel procedure described in the first part of this paper. The subsequent calcining and sintering of th e PNZT powders are described. The oxides formation occurs at lower temperat ures than the one reported in the literature, possibly due to the sol-gel p rocedure used in the synthesis of the precursor powders. After calcination and sintering, ceramics with a mostly intragranular fracture were obtained. The dielectric, piezoelectric and ferroelectric properties of some ceramic materials obtained were measured. The results obtained for the values of t he dielectric parameters are: max. dielectric constant, epsilon'(boolean OR )19.000, dielectric dissipation, tg delta (boolean OR)0.015 and the Curie t emperature around 225 degreesC. The piezoelectric properties measured: coup ling factors in the radial mode, K(p)(boolean OR)35%, and in the thickness mode, K-t = 47%, and the mechanical quality factor, Q(m)= 95.6, makes these ceramic materials as piezoelectrics. But their best performance is as ferr oelectric materials since the hysteresis cycles attained are squared.