Evolution of chemical bonding and spin-pairing energy in ferropericlase across Its spin transition
- The evolution of chemical bonding in ferropericlase, (Mg,Fe)O, with pressure may affect the physical and chemical properties of the Earth's lower mantle. Here, we report high-pressure optical absorption spectra of single-crystalline ferropericlase ((Mg0.87Fe0.13)O) up to 135 GPa. Combined with a re-evaluation of published partial fluorescence yield X-ray absorption spectroscopy data, we show that the covalency of the Fe-O bond increases with pressure, but the iron spin transition at 57-76.5 GPa reverses this trend. The qualitative crossover in chemical bonding suggests that the spin-pairing transition weakens the Fe-O bond in ferropericlase. We find, that the spin transition in ferropericlase is caused by both the increase of the ligand field-splitting energy and the decrease in the spin-pairing energy of high-spin Fe2+.
| Author details: | Lukas SchifferleORCiDGND, Sergey S. LobanovORCiD |
|---|---|
| DOI: | https://doi.org/10.1021/acsearthspacechem.2c00014 |
| ISSN: | 2472-3452 |
| Title of parent work (English): | ACS Earth and Space Chemistry |
| Publisher: | American Chemical Society |
| Place of publishing: | Washington |
| Publication type: | Article |
| Language: | English |
| Date of first publication: | 2022/03/03 |
| Publication year: | 2022 |
| Release date: | 2023/12/13 |
| Tag: | bond strength; covalency; diamond anvil cell; high-pressure; iron; spin; transition |
| Volume: | 6 |
| Issue: | 3 |
| Number of pages: | 12 |
| First page: | 788 |
| Last Page: | 799 |
| Funding institution: | Helmholtz Young Investigators Group CLEAR [VH-NG-1325] |
| Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
| DDC classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
| 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften | |
| Peer review: | Referiert |
