Lattice instabilities in bulk EuTiO.sub.3./sub..

0399505 - FZÚ 2014 RIV US eng J - Journal Article
Bessas, D. - Rushchanskii, K.Z. - Kachlik, M. - Disch, S. - Gourdon, O. - Bednarcik, J. - Máca, K. - Sergueev, I. - Kamba, Stanislav - Ležaič, M. - Hermann, R.P.
Lattice instabilities in bulk EuTiO₃.
Physical Review. B. Roč. 88, č. 14 (2013), "144308-1"-"144308-9". ISSN 1098-0121
R&D Projects: GA ČR GAP204/12/1163; GA MŠMT LD12026
Institutional support: RVO:68378271
Keywords : structural phase transition * phonons * lattice dynamics
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 3.664, year: 2013

The phase purity and the lattice dynamics in bulk EuTiO3 were investigated both microscopically, using x-ray and neutron diffraction, 151 Eu-Mössbauer spectroscopy, and 151 Eu nuclear inelastic scattering, and macroscopically using calorimetry, resonant ultrasound spectroscopy, and magnetometry. A stiffening on heating around room temperature is indicative of a phase transition similar to the one observed in SrTiO3, however, although previous studies reported the structural phase transition to the tetragonal I4/mcm phase our detailed sample purity analysis and thorough structural studies using comple mentary techniques did not confirm a direct phase transition. Instead, in the same temperature range, Eu delocalization is observed which might explain the lattice dynamical instabilities.
Permanent Link: http://hdl.handle.net/11104/0226746