Investigation of local structure of lead-free relaxor Ba(Ti0.70Sn0.30)O3 by Raman spectroscopy

The local structure of Ba(Ti-0.70,Sn-0.30)O-3 (BSnT) was investigated using micro Raman spectroscopy from 80 to 500 K, which indicated three local phase sequences. The dielectric spectroscopy studies illustrated freezing of polar nano-regions (PNR) below 95 K, merger of frequency dispersion at 220 K, and the origin of polar nano-regions at 482 K. The temperature evolution of Raman spectra, basically integrated intensity, indicates non-ergodic relaxor phase below 100 K, mature ergodic phase between 100 and 200 K, and the existence of ergodic polar clusters until 450 K, and above paraelectric phase. The observation of local phase sequences by Raman spectra are in agreement with dielectric spectroscopy anomalies. Copyright (C) 2008 John Wiley & Sons, Ltd.