Polar clusters in relaxor (Pb,La)(Zr,Ti)O-3 revealed by second harmonic generation

Polarization ordering in Pb1-xLax(Zr0.65Ti0.35)(0.98)O-3 ceramics for x=8%, 9% and 9.5% (PLZT x/65/35) was detected from the temperature dependence of the averaged second harmonic generation (SHG) intensity. In PLZT 8/65/35 i t shows two drops near the freezing transition (at about 50 degreesC) and s lightly below the Burns temperature (about 350 degreesC). The SHG intensity exhibits peaks at 90 and 355 degreesC detected in both PLZT compositions u sing slow heating runs, which disappear for faster temperature runs. This i ndicates an unusual increase in dipole ordering with a very slow relaxation time. (C) 2001 American Institute of Physics.