Structural, micro-structural and electric properties were investigated in lanthanum modified PZT perovskite ferroelectric ceramics as a function of the lanthanum content near the morphotropic phase boundary composition Zr/Ti=53/47. Ceramic samples were obtained by the conventional solid state reaction using high purity reagents. The X-ray diffraction results revealed the presence of the tetragonal phase with a continuous decrease of the tetragonality factor (c/a) with increasing the La content. High density ceramic bodies were obtained as confirmed by scanning electron microscopy. A decrease of the ferroelectric-paraelectric phase transition temperature (Tm) with increasing lanthanum content was discussed with respect to the incorporation of the La3+ cation in the PZT crystalline lattice.
ferroelectric ceramics; microstructure; dielectric properties; PZT; La