Polar clusters in relaxor (Pb,La)(Zr,Ti)O3 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 it shows two drops near the freezing transition (at about 50 degreesC) and slightly below the Burns temperature (about 350 degreesC). The SHG intensity exhibits peaks at 90 and 355 degreesC detected in both PLZT compositions using slow heating runs, which disappear for faster temperature runs. This indicates an unusual increase in dipole ordering with a very slow relaxation time. (C) 2001 American Institute of Physics.