Synthesis and low temperature fluorination of the alkaline-earth palladates Ba2-xSrxPdO3 (x = 0-2)

Baikie, T.; Young, N. A.; Francesconi, M. G.

Abstract

Since the discovery of superconductivity in Sr2CuO2F2+δ there has been an increased interest in ternary oxide-fluorides. Sr2CuO2F2+δ is prepared via low temperature (T = 220 °C) reaction routes. Low temperature fluorination induces an interesting structural rearrangement in the parent compound Sr2CuO3, which is a one-dimensional material containing linear chains of vertex sharing CuO4 squares along the crystallographic b axis. Upon fluorination, one oxide is substituted by two fluorides and Cu2+ becomes octahedrally coordinated by four oxides and two fluorides. The fluorinated compound Sr2CuO2F2+δ displays the T-type structure (La2CuO4). Insertion of excess fluorine, δ, also takes place and this fluorine occupies interstitial sites in the T structure. Although the starting material Ca2CuO3 is isostructural to Sr2CuO3, Ca2CuO2F2+δ displays the T′ (Nd2CuO4) structure due to the smaller radius of Ca2+ compared to that of Sr2+. The alkaline-earth palladates with the general formula A2PdO3 (A = Ba, Sr) are isostructural with the A2CuO3 (A = Ca, Sr) materials. We prepared the Ba2-xSrxPdO3 (x = 0-2) series and performed low temperature fluorination, which led to the synthesis of the series Ba2-xSrxPdO2F2+δ (0 ≤ x ≤ 1.5). All the compounds in the Ba2-xSrxPdO2F2+δ series show T′ structure (Ca2CuO2F2+δ). Similarities and differences with Sr2CuO2F2+δ and Ca2CuO2F2+δ will be discussed. © 2007 Elsevier Ltd. All rights reserved.

Citation

Baikie, T., Young, N. A., & Francesconi, M. G. (2007). Synthesis and low temperature fluorination of the alkaline-earth palladates Ba2-xSrxPdO3 (x = 0-2). Progress in Solid State Chemistry, 35(2-4 SPEC. ISS.), 265-279. https://doi.org/10.1016/j.progsolidstchem.2007.01.010

• Journal Article Type: Review
• Online Publication Date: Jan 13, 2007
• Publication Date: Jul 4, 2007
• Deposit Date: Dec 9, 2020
• Journal: Progress in Solid State Chemistry
• Print ISSN: 0079-6786
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 35
• Issue: 2-4 SPEC. ISS.
• Pages: 265-279
• DOI: https://doi.org/10.1016/j.progsolidstchem.2007.01.010
• Public URL: https://hull-repository.worktribe.com/output/3590384
• Publisher URL: https://www.sciencedirect.com/science/article/abs/pii/S0079678607000064?via%3Dihub