title: Concentration- and Temperature-Induced Phase Transitions in PrAlO3-SrTiO3 System.
abstract: Single-phase mixed aluminates-titanates Pr1-x Sr x Al1-x Ti x O3 (x = 0.1, 0.2, 0.3, 0.5, 0.7) with rhombohedral perovskite structure were prepared by solid-state reaction technique at 1823-1873 K. Morphotropic rhombohedral-to-cubic phase transition in Pr1-x Sr x Al1-x Ti x O3 series is predicted to occur at x = 0.88. The temperature-induced structural phase transition R  [Formula: see text]  с - Pm [Formula: see text]  m in Pr0.5Sr0.5Al0.5Ti0.5O3, detected at 930 K by in situ high-temperature X-ray synchrotron powder diffraction, occurs at considerably lower temperature as the corresponding transformation in the parent compound PrAlO3 (1770 K). Such remarkable drop of the transition temperature is explained by gradual decrease of the perovskite structure deformation in the Pr1-x Sr x Al1-x Ti x O3 series with increasing Sr and Ti contents as a consequence of the increasing Goldschmidt tolerance factor. For Pr0.3Sr0.7Al0.3Ti0.7O3 phase, a sequence of the low-temperature phase transformation R  [Formula: see text]  с - Immb(C2/m) - I4/mcm was detected.
authors.affiliation: Lviv Polytechnic National University, 12 Bandera Street, 79013, Lviv, Ukraine. crystal-lov@polynet.lviv.ua.
authors.forename: Leonid
authors.initials: L
authors.lastname: Vasylechko
authors.affiliation: Lviv Polytechnic National University, 12 Bandera Street, 79013, Lviv, Ukraine. stepchukroman@gmail.com.
authors.forename: Roman
authors.initials: R
authors.lastname: Stepchuk
authors.affiliation: Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187, Dresden, Germany. prots@cpfs.mpg.de.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Prots
authors.affiliation: Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187, Dresden, Germany. Helge.Rosner@cpfs.mpg.de.
authors.forename: Helge
authors.initials: H
authors.lastname: Rosner
keywords: Crystal structure; Perovskite aluminates and titanates; Phase transitions; Solid solution