Low-Temperature Raman Studies of Pb(ZrxTi1-x)O3 and Pb1-3y/2NdyTiO3 Ceramics

Raman scattering studies of lead zirconate titanate Pb(Zr x Ti1-x )O3 (PZT), 0.10≤x≤0.80, and Nd-modified lead titanate Pb1-3y/2Nd y TiO3 (PNT), y=0.02, 0.10, bulk ceramics were carried out at ambient temperatures between 4.2 and 297 K. Our measurements reveal splitting of the E⊕B 1 symmetry peak at low temperatures in both PZT and PNT samples. Splitting or a very asymmetrical line shape of the three other E(TO) peaks in the PZT and PNT samples was also found. These findings are related to the precursor effects. We also discuss the phase stability of lead titanate based perovskites from the point of view of our experimental results and recent theoretical calculations. A simple model explaining the differences between the low-frequency Raman spectra of tetragonal and trigonal PZTs is outlined.