HREM studies of intergrowths in Sr2[Srn-1TinO3n+1] Ruddlesden-Popper phases synthesized by mechanochemical activation

Hungria, T., MacLaren, I., Fuess, H., Galy, J. and Castro, A. (2008) HREM studies of intergrowths in Sr2[Srn-1TinO3n+1] Ruddlesden-Popper phases synthesized by mechanochemical activation. Materials Letters, 62(17-18), pp. 3095-3098. (doi: 10.1016/j.matlet.2008.01.110)

Abstract

A mechanochemical activation route has been applied in order to obtain the <i>n</i>=1–4 and ∞ members of the Sr₂[Sr_n₋₁Ti_nO_3n+1] Ruddlesden– Popper series from different (<i>n</i>+1)SrO:nTiO₂ mixtures. The mechanosynthesis of SrTiO₃ and Sr₂TiO₄ was observed during the milling process from the initial stoichiometric mixture, but in the cases of the <i>n</i>=2–4 members, a subsequent thermal treatment was needed. The synthesis protocol of Sr₃Ti₂O₇ has been greatly improved and this compound can be isolated as a single, crystalline phase after annealing at 800°C. In the case of Sr₄Ti₃O₁₀ and Sr₅Ti₄O₁₃, the formation temperature was also decreased, but members with <i>n</i>=3 and 4 could not be isolated. Detailed investigations using electron microscopy methods (TEM, HREM and SAED) were carried out in the samples corresponding to <i>n</i>=2–4. Although a single ordered Sr₃Ti₂O₇ structure is dominant in the sample corresponding to <i>n</i>=2, a few intergrowths of other Ruddlesden–Popper phases were observed. In the cases of <i>n</i>=3 and 4, the intergrowths of Ruddlesden–Popper phases are more frequent than in the <i>n</i>=2 composition and are randomly distributed in the sample. The more frequent occurrence of such stacking faults, with increasing <i>n</i> value, leads to a somewhat disordered layer stacking sequence.

• Item Type: Articles
• Keywords: Perovskites, crystal structure, electron microscopy.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: MacLaren, Dr Ian
• Authors: Hungria, T., MacLaren, I., Fuess, H., Galy, J., and Castro, A.
• Subjects: Q Science > QC Physics
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Materials Letters
• Publisher: Elsevier
• ISSN: 0167-577X
• ISSN (Online): 1873-4979
• Published Online: 08 February 2008
• Copyright Holders: Copyright © 2008 Elsevier
• First Published: First published in Materials Letters 62(17-18):3095-3098
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher.