Lattice parameters and structural phase transition of lanthanum titanate perovskite, La0.68(Ti0.95,Al0.05)O3

Lattice parameters and the structural phase transition of La(0.68)(Ti(0.95),Al(0.05))O(3) have been investigated in situ in the temperature range 301-689 K by the synchrotron radiation powder diffraction (SR-PD) technique. High-angular-resolution SR-PD is confirmed to be a powerful technique for det...

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Veröffentlicht in:Journal of synchrotron radiation. - 1999. - 10(2003), Pt 3 vom: 01. Mai, Seite 228-32
1. Verfasser: Ali, Roushown (VerfasserIn)
Weitere Verfasser: Yashima, Masatomo
Format: Aufsatz
Sprache:English
Veröffentlicht: 2003
Zugriff auf das übergeordnete Werk:Journal of synchrotron radiation
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:Lattice parameters and the structural phase transition of La(0.68)(Ti(0.95),Al(0.05))O(3) have been investigated in situ in the temperature range 301-689 K by the synchrotron radiation powder diffraction (SR-PD) technique. High-angular-resolution SR-PD is confirmed to be a powerful technique for determining precise lattice parameters around a phase-transition temperature. The title compound exhibits a reversible phase transition between orthorhombic and tetragonal phases at 622.3 +/- 0.6 K. The following results were obtained: (i) the lattice parameters increased continuously with temperature, while the b/a ratio decreased continuously with temperature and became unity at the orthorhombic-tetragonal transition point; (ii) no hysteresis was observed between the lattice-parameter values measured on heating and on cooling. Results (i) and (ii) indicate that the orthorhombic-tetragonal phase transition is continuous and reversible. The b/a ratio is found to exhibit a more continuous temperature evolution than does the order parameter for a typical second-order phase transition based on Landau theory
Beschreibung:Date Completed 02.10.2003
Date Revised 05.06.2019
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:0909-0495