Springer Verlag, Hyperfine Interactions, 1-3(198), p. 1-4
DOI: 10.1007/s10751-010-0204-5
HFI / NQI 2010, p. 347-350
DOI: 10.1007/978-94-007-1269-0_56
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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.