Lattice dynamics study of high-quality strontium bismuth tantalate single crystals

authors	Almeida, A; Chaves, MR; Amorin, H; Costa, MEV; Kholkin, AL
nationality	International
journal	JOURNAL OF PHYSICS-CONDENSED MATTER
keywords	FERROELECTRIC PHASE-TRANSITION; LAYERED PEROVSKITE SRBI2TA2O9; ELECTRONIC-STRUCTURE; THIN-FILMS; RAMAN; CERAMICS
abstract	Raman scattering was investigated in high-quality SrBi2Ta2O9 (SBT) single crystals prepared by the self-flux solution method. The Raman spectra in the range 6-1800 cm(-1) were monitored as a function of temperature both below and above the ferroelastic-ferroelectric phase transition at about 600 K. The behaviour of the soft ferroelectric mode and of its damping coefficient near the phase transition indicates a strong coupling with an acoustical phonon. The results provide clear evidence for a crossing over from a displacive to an order-disorder component and they are discussed in terms of a complex sequence of the phase transitions in SBT.
publisher	IOP PUBLISHING LTD
issn	0953-8984
year published	2005
volume	17
issue	48
beginning page	7605
ending page	7612
digital object identifier (doi)	10.1088/0953-8984/17/48/012
web of science category	Physics, Condensed Matter
subject category	Physics
unique article identifier	WOS:000234268600014