X-Ray Scattering Study of the Transition Dynamics in Relaxor Ferroelectric Lead (Magnesium(1/3) Niobium(2/3)) Oxygen(3) (Pmn)

157 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2000.Thermal diffuse scattering measurements were performed at several temperatures. A [011] transverse optic soft mode was determined to exist. The temperature dependence of this phonon mode was carefully studied as the transition is approached, and down to 40 K. The q-dependency of the freezing process was carefully studied, and it was shown that the freezing takes place simultaneously at the zone center (ZC) and zone boundary (ZB). Coupled with results obtained from the SRO peak, these results imply that both ferroelectric and anti-ferroelectric fluctuations are present in the structure. (Abstract shortened by UMI.).U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD