Dynamical properties of the relaxor ferroelectric 0.71Pb(Ni1/3Nb2/3)O3-0.29PbTiO3 probed by Brillouin and Raman scattering

Structural phase transitions in relaxor ferroelectric materials remain to be one of the most puzzling issues in solid-state physics. In the present work, we have investigated relaxational and vibrational properties of a relaxor ferroelectric 0.71Pb(Ni
1/3
Nb
2/3
)O
3
-0.29PbTiO
3
single crystal by means of inelastic light scattering measurements. Analysis based on the spectra has showed anomalous behaviors at Burn's temperature T
d
, freezing temperature T
f
, those are related to a development of polar nanoregions (PNRs). PNR must play a key role in relaxor nature, and obtained results provide insight into the relaxational processes in the PNR and into how they develop below T
f
.