The local atomic structure and phonons in Ba0.5Sr0.5TiO3 Original Research Article

The study of the local atomic structure of the solid solution of Ba0.5Sr0.5TiO3 (BST) has shown that its microscopic properties are quite distinct from those of the end members of the series, BaTiO3 (BTO) and SrTiO3 (STO). In contrast to BTO and STO, the BST structure changes as a function of temperature at short length scales, but not on average. However, from the extraction of phonon dynamics from the diffraction measurement, the presence of a soft mode behavior similar to the soft mode observed in BTO is suggested. This indicates that lattice instabilities are driven by mechanisms that are similar to those observed in the ferroelectric transition of BTO and the structural transition of STO.