Optical and electro-optical characteristics of hot-pressing: (Pb1-xlax)TiO3 ferroelectric ceramics

Abstract

La-modified PbTiO3-based ceramics (PLT) are the subject of many studies in term of piezoelectric and pyroelectric applications, but the processing of PLT to optimize their transparency and electro-optical properties has not been studied in detail. Ferroelectric (Pb1-xLax)TiO3 (PLT) ceramics, with 0.18 ≤ x ≤ 0.23, were produced by a solid state reaction and uniaxially hot pressing for 3h at a temperature of 1220° C, and a pressure of ~6,0 MPa. High density, translucent reddish color and high dc conductivity were observed for all compositions. Nevertheless appropriate thermal treatments in an O2 atmosphere, after hot pressing, led to ceramics with good properties for dielectric, optical and electro-optical studies. The heat-treated samples revealed a homogeneous microstructure, absence of second phases, increased of the transmittance in the visible and infrared range and reduced dc conductivity. These features allowed the electro-optical coefficient of the (Pb,La)TiO3 system to be calculated.