Phonon mode softening at the ferroelectric transition in Eu0.5Ba0.5TiO3
- 71 Downloads
We have observed the effects of phonon mode softening at the ferroelectric transition in Eu0.5Ba0.5TiO3 by 151Eu Mössbauer spectroscopy. Both Eu2+ and Eu3+ spectral components are observed in the relative area ratio of 90% : 10% and both show a decrease in subspectral area at the transition, centred at 175 K, due to phonon mode softening. Surprisingly, the temperature dependence of the f-factor shows a much stronger response in the Eu3+ component than in the Eu2+ one. Preliminary analysis of neutron powder diffraction data rules out the possibility that some of the europium might be located on titanium sites.
KeywordsFerroelectric Mössbauer spectroscopy Electron electric dipole moment
Unable to display preview. Download preview PDF.
- 4.Anderson, P.W.: Qualitative considerations on the statistics of the phase transition in BaTiO3-type ferroelectrics. In: Skanavi, G.I. (ed.) Fizika Dielektrikov, pp. 290–294. Akad. Nauk., Moscow (1960)Google Scholar
- 8.Shannon, R.D.: Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Cryst. A32, 751–767 (1976)Google Scholar