Light scattering and domain structure of ferroelectric PLZT family ceramics

Abstract

Transparent ferroelectric PLLZT ceramics were prepared by partial substitution of (La_0.5Li_.5) complex ions for Pb ones in Pb(Zr,Ti)O_3. Chemical formula of the ceramics is presented as [Pb_{1 − x} (La_0.5Li_0.5) _x ] (Zr _x Ti_{1 − x} )O₃. In the range of 0 <x < 0.6, the ferroelectric properties were similar to those of PLZT. Light scattering was induced by discontinuous refractive index at boundaries such as domain walls and crystal grains in the ceramics. The intensity of scattered light was dependent on the average grain size and the direction of electric polarization. Biasing field and frequency dependence of the dielectric constant was explained by 180[ddot] domain reverse and 90[ddot] domain rotation. The dc bias field dependence of effective birefringence was also discussed.

Key Words:

• Light scattering
• birefringence
• 180° and 90° domains
• dielectric constant
• polarization