Abstract:

In this study, lanthanum-substituted lead zirconate titanate (PLZT) ceramics with the general formula Pb₁₋ₓLaₓ (Zr₁₋ᵧTiᵧ) ₁₋ₓ/₄O₃ were prepared through a modified sol–gel route and densified by controlled sintering to yield dense ferroelectric bodies. The work systematically examines how progressive lanthanum addition affects the structural, microstructural, dielectric and electromechanical response of the resulting ceramics. X-ray diffraction (XRD) verified that a well-crystallised, single-phase perovskite had formed without any traceable secondary phase, while scanning electron microscopy (SEM) revealed a compact, uniform microstructure with refined grains. Density and porosity data confirmed that sintering produced effective densification. The dielectric study showed that raising the lanthanum level modified the ferroelectric transition, lowering the Curie point while increasing the permittivity in the vicinity of the morphotropic phase boundary (MPB). Piezoelectric testing recorded a marked rise in both the charge coefficient (d₃₃) and the planar coupling factor (kₚ) at optimum lanthanum contents. These gains are linked to greater domain mobility, reduced lattice distortion and a finer microstructure introduced by lanthanum substitution. Overall, the findings establish sol–gel-derived PLZT as a strong candidate for advanced piezoelectric sensors, actuators, ultrasonic transducers, energy-harvesting units and related smart-electronic devices.

Keywords:

PLZT ceramics, Sol-gel synthesis, Ferroelectric materials, Piezoelectric properties, X-ray diffraction, Dielectric characteristics, Electromechanical coupling.

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Methods