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Across the Structural Re-Entrant Transition in BaFe2(PO4)2: Influence of the Two-Dimensional Ferromagnetismстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 13 марта 2014 г.
- Авторы: David Rénald, Pautrat Alain, Filimonov Dmitry, Kabbour Houria, Vezin Hervé, Whangbo Myung-Hwan, Mentré Olivier
- Журнал: Journal of the American Chemical Society
- Том: 135
- Номер: 35
- Год издания: 2013
- Издательство: American Chemical Society
- Местоположение издательства: United States
- Первая страница: 13023
- Последняя страница: 13029
- DOI: 10.1021/ja404697b
- Аннотация: BaFe2(PO4)2 was recently prepared by hydrothermal synthesis and identified as the first two-dimensional (2D) Ising ferromagnetic oxide, in which honeycomb layers made up of edge-sharing FeO6 octahedra containing high-spin Fe(2+) ions (S = 2) are isolated by PO4 groups and Ba(2+) cations. BaFe2(PO4)2 has a trigonal R-3 structure at room temperature but adopts a triclinic P-1 structure below 140 K due to the Jahn-Teller (JT) instability arising from the (t2g)(4)(eg)(2) configuration. The triclinic crystal structure was refined to find significantly distorted Fe(2+)O6 octahedra in the honeycomb layers while the distortion amplitude QJT was estimated to 0.019 Å. The JT stabilization energy is estimated to be ∼7 meV per formula unit by DFT calculations. Below ∼70 K, very close to the ferromagnetic transition temperature Tc = 65.5 K, the structure of BaFe2(PO4)2 returns to a trigonal R-3 structure in the presence of significant ferromagnetic domains. This rare re-entrant structural transition is accompanied by a discontinuous change in the quadrupolar splitting of Fe(2+), as determined by Mössbauer spectroscopy. EPR measurements show the presence of magnetic domains well above Tc , as expected for a ferromagnetic 2D Ising system, and support that the magnetism of BaFe2(PO4)2 is uniaxial (g⊥ = 0).
- Добавил в систему: Филимонов Дмитрий Сергеевич