La2SrCr2O7F2: A Ruddlesden-Popper oxyfluoride containing octahedrally coordinated Cr(4+) centers

Journal article

The low-temperature fluorination of the n = 2 Ruddlesden-Popper phase La2SrCr2O7 yields La2SrCr2O7F2 via a topochemical fluorine insertion reaction. The structure-conserving nature of the fluorination reaction means that the chromium centers of the initial oxide phase retain an octahedral coordination environment in the fluorinated product, resulting in a material containing an extended array of apex-linked Cr(4+)O6 units. Typically materials containing networks of octahedrally coordinated Cr(4+) centers can only be prepared at high pressure; thus, the preparation of La2SrCr2O7F2 demonstrates that low-temperature topochemical reactions offer an alternative synthesis route to materials of this type. Neutron diffraction, magnetization, and μ(+)SR data indicate that La2SrCr2O7F2 undergoes a transition to an antiferromagnetic state below TN ≈ 140 K. The structure-property relations of this phase and other Cr(4+) oxide phases are discussed.

Authors: Zhang, R; Read, G; Lang, F; Lancaster, T; Blundell, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: Inorganic Chemistry
• Volume: 55
• Issue: 6
• Pages: 3169–3174
• Publication date: 2016-03-09
• Acceptance date: 2016-03-01
• DOI: 10.1021/acs.inorgchem.6b00114
• ISSN: 1520-510X and 0020-1669
• Pmid: 26959515
• Language: English
• Keywords: SBTMR; Journal Article; Research Support, Non-U.S. Gov't