Unveiling pressure-induced anomalous shear behavior and thermoelasticity of α-Fe2O3 hematite at high pressure
Summary: Hematite (α-Fe2O3), as an important end-member of FeO-Fe2O3 series, has garnered particular interest for its peculiar high pressure-temperature (P-T) behavior, structural stability and elasticity, and the unclear role of Fe3+ in the nature and dynamics of the Earth’s mantle. Here, we report...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-02-01
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| Series: | iScience |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2589004225001658 |
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| Summary: | Summary: Hematite (α-Fe2O3), as an important end-member of FeO-Fe2O3 series, has garnered particular interest for its peculiar high pressure-temperature (P-T) behavior, structural stability and elasticity, and the unclear role of Fe3+ in the nature and dynamics of the Earth’s mantle. Here, we report a pronounced pressure-induced anomaly in the shear behavior of hematite at room temperature and ∼3.5 GPa owing to the (weak)ferromagnetic-to-antiferromagnetic Morin transition driven by pressure and temperature. Unexpectedly, this phase-transition-driven anomalous behavior at high P-T is absent in the compressional velocities. The bulk and shear moduli, as well as their pressure and temperature dependences for Fe2O3 hematite are reported, yielding KS0 = 235.5(8) GPa, G0 = 88.0(3) GPa, әKS/әP = 3.29(25), dG/dP = 1.36(10), әKS/әT = −0.027(2) GPa/K, and әG/әT = −0.019(1) GPa/K. These findings and high-P thermoelasticity will be of significant importance for good understanding of the underlying mechanism for phase-transition-induced anomaly at high pressures and temperatures in the shear behavior of Fe-O materials. |
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| ISSN: | 2589-0042 |