Université de Fribourg

Optical probe of ferroelectric order in bulk and thin-film perovskite titanates

Rössle, Matthias ; Wang, Chen Nan ; Maršík, Premysl ; Yazdi-Rizi, M. ; Kim, Kyung Wan ; Dubroka, Adam ; Marozau, Ivan ; Schneider, C. W. ; Humlíček, J. ; Baeriswyl, Dionys ; Bernhard, Christian

In: Physical Review B, 2013, vol. 88, no. 10, p. 104110

We have measured the temperature dependence of the direct band gap Eg in SrTiO₃ and BaTiO₃ and related materials with quantum-paraelectric and ferroelectric properties using optical spectroscopy. We show that Eg exhibits an anomalous temperature dependence with pronounced changes in the vicinity of the ferroelectric transition that can be...