摘要
A layered Sr2Co0.5Ir0.5O4(space group I4/mmm) perovskite of the K2NiF4structure type was synthesized as a single-phase sample. Neutron powder diffraction measurements revealed full site occupancy of oxygen atoms. The Co3+/Ir5+valence states were evaluated by a combination of X-ray absorption and X-ray photoemission spectroscopy as well as by magnetization measurements, and thus the differences to the parent compounds Sr2CoO4and Sr2IrO4with similar structures were confirmed. Co-K edge EXAFS studies indicated a long average Co–O distance of 1.967 Å suggesting a high-spin state of the Co3+ion in Sr2Co0.5Ir0.5O4. No long-range magnetic ordering down to 4 K was detected by neutron powder diffraction, probably hindered by the random distribution of Co and Ir cations in the Sr2Co0.5Ir0.5O4structure. High-pressure synchrotron powder diffraction studies showed stability of the Sr2Co0.5Ir0.5O4structure up to at least 27 GPa at room temperature. A maximum in the c/a ratio at 10 GPa together with an anomaly in the pressure dependence of the unit-cell volume could be a sign of a change in the spin state of the Co ions under pressure.
原文 | English |
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頁(從 - 到) | 587-595 |
頁數 | 9 |
期刊 | European Journal of Inorganic Chemistry |
卷 | 2017 |
發行號 | 3 |
DOIs | |
出版狀態 | Published - 2017 |