Dynamical mechanism of phase transitions in a-site ferroelectric relaxor (Na1/2Bi1/2)TiO3

Simple item page
dc.contributor.authorDeng, GCen_AU
dc.contributor.authorDanilkin, SAen_AU
dc.contributor.authorZhang, HWen_AU
dc.contributor.authorImperia, Pen_AU
dc.contributor.authorLi, XBen_AU
dc.contributor.authorZhao, Xen_AU
dc.contributor.authorLuo, HQen_AU
dc.date.accessioned2016-07-05T23:31:03Zen_AU
dc.date.available2016-07-05T23:31:03Zen_AU
dc.date.issued2014-10-13en_AU
dc.date.statistics2016-07-06en_AU
dc.description.abstractThe dynamical phase transition mechanism of (Na1/2Bi1/2)TiO3 (NBT) was studied using inelastic neutron scattering. Softening was observed of multiple phonon modes in the phase transition sequence of NBT. As usual, the softening of the zone center transverse optical modes Δ5 and Σ3 was observed in the (200) and (220) zones, showing the Ti vibration instabilities in TiO6 octahedra for both cubic-tetragonal (C-T) and tetragonal-rhombohedral (T-R) phase transitions. In these two phase transitions, however, Ti4+ has different preferential displacement directions. Surprisingly, the longitudinal optic mode also softens significantly toward the zone center in the range of the transition temperature, indicating the Na+/Bi3+ vibration instability against TiO6 octahedra during the T-R phase transition. Strong inelastic diffuse scattering shows up near M(1.5, 0.5, 0) and R(1.5, 1.5, 0.5) in the tetragonal and rhombohedral phases, respectively, indicating the condensations of the M3 and R25 optic modes for the corresponding transitions. This reveals the different rotation instabilities of TiO6 in the corresponding transition temperature range. Bottleneck or waterfall features were observed in the dispersion curves at certain temperatures but did not show close correlations to the formation of polar nanoregions. Additional instabilities could be the origin of the complexity of phase transitions and crystallographic structures in NBT. © 2014 American Physical Society.en_AU
dc.identifier.articlenumber134104en_AU
dc.identifier.citationDeng, G., Danilkin, S., Zhang, H., Imperia, P., Li, X., Zhao, X. & Luo, H. (2014). Dynamical mechanism of phase transitions in a-site ferroelectric relaxor (Na1/2Bi1/2)TiO3. Physical Review B, 90(13), 134104. doi: 10.1103/PhysRevB.90.134104en_AU
dc.identifier.govdoc6797en_AU
dc.identifier.issn2469-9950en_AU
dc.identifier.issue13en_AU
dc.identifier.journaltitlePhysical Review Ben_AU
dc.identifier.urihttp://dx.doi.org/10.1103/PhysRevB.90.134104en_AU
dc.identifier.urihttp://apo.ansto.gov.au/dspace/handle/10238/7144en_AU
dc.identifier.volume90en_AU
dc.language.isoenen_AU
dc.publisherAPS Physicsen_AU
dc.subjectPhononsen_AU
dc.subjectVapor condensationen_AU
dc.subjectCrystallographyen_AU
dc.subjectNeutronsen_AU
dc.subjectOptical modesen_AU
dc.subjectTransition temperatureen_AU
dc.titleDynamical mechanism of phase transitions in a-site ferroelectric relaxor (Na1/2Bi1/2)TiO3en_AU
dc.typeJournal Articleen_AU
Files
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Journal Articles