Synthèse et caractérisation d’un nouveau matériau de céramique de type Zirconat-Titanate de plomb (PZT)

Abstract

The aim of this thesis is the synthesis, structural, and physical characterization of a novel ceramic material of the PZT type in the ternary system Pb1-xSmx[(Zr0.52Ti0.48)0.9(Mo1/3In2/3)0.05(Zn1/3Sb2/3)0.05]O3 (PSZT-PSMI-PSZS), with 00 ≤ x ≤ 0.08. The ceramics were prepared via solid-state reaction and sintered at 1150°C. The results reveal a perovskite structure with a secondary phase, whose intensity increases with the Sm concentration, as confirmed by X-ray diffraction (XRD), Rietveld refinement, and Raman spectroscopy. Microscopic examination shows variations in the microstructure, with maximum density and grain size observed for x ≤ 0.02. Optimal electrical properties are achieved for x = 0.00 and x = 0.02, with a high dielectric constant (8,578 and 8,574, respectively), a Curie temperature of 303°C, and low dielectric loss (Tan δ at Tc = 0.34) for x = 0.00. Conductivity studies reveal a negative temperature coefficient of resistance for all samples. Furthermore, optimal piezoelectric and ferroelectric properties are observed for x = 0.02, including a high piezoelectric coefficient d33 (310 pC/N), improved electromechanical coefficients (kp = 60 %, k31 = 35 %), and strong ferroelectric properties (Pr = 17.71 μC/cm2, Ps = 22.75 μC/cm2, Ec = 10.16 kV/cm, d*33 = 427.57 pm/V, Smax = 0.17 %). Additionally, the correlation between electrical characteristics and Sm2O3 doping is discussed. This research provides valuable insights into the properties of Sm2O3 -doped PZT ceramics.