Soft phonon anomalies in the relaxor ferroelectric Pb(Zn(1/3)Nb(2/3))0.92Ti0.08O3
Neutron inelastic scattering measurements of the polar transverse optic phonon mode dispersion in the cubic relaxor Pb(Zn(1/3)Nb(2/3))0.92Ti0.08O3 at 500 K reveal anomalous behavior in which the optic branch appears to drop precipitously into the acoustic branch at a finite value of the momentum transfer q = 0.2 A(-1) measured from the zone center. We speculate that this behavior is the result of nanometer-sized polar regions in the crystal.
Gehring
PM
NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
Park
S
Shirane
G