FeSbO4exhibits an extraordinarily high electrical resistance of ∼650 Gω at pressures near 7 GPa at room temperature. Pressure-induced electrical transport measurements reveal a large resistance increase of 106compared to ambient pressure. This is the result of a very strong Coulomb repulsion between localized iron 3d-electrons caused by an abrupt shortening of the axial Fe(3d)/Sb(5s)-O(2p) σ-bonds in the Fe/SbO6octahedra as verified by in situ X-ray diffraction (XRD) study. Subsequent and concomitant strengthening of Sb-O and weakening of Fe-O bonds drive FeSbO4into a Mott insulating state. Upon increasing pressure to 13 GPa, XRD and optical absorption spectroscopy further confirm a first-order phase transition from a tetragonal insulator with Fe3+in a high spin state to an orthorhombic semiconductor with Fe3+in a low spin state without any metallization. Powder diffraction and transmission electron microscope images reveal that the recovered sample after pressure release preserves the high-pressure orthorhombic structure albeit with Fe3+in a high spin state and maintains its high resistance. The behavior at moderate pressures might be useful for potential applications in electronic switches, piezoresistive sensors, and other electronic devices.
|Number of pages||8|
|Journal||Journal of Physical Chemistry C|
|Publication status||Published - 2022 May 5|
Bibliographical noteFunding Information:
This work was supported by the Leader Researcher program (Grant NRF-2018R1A3B1052042) of the Korean Ministry of Science, ICT and Planning (MSIP).
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films