FeO
wüstite · iron(II) oxide, ferrous oxide
Wüstite is a stable, semiconducting iron oxide utilized primarily as a model material in the study of conversion-type anodes for electrochemical energy storage.
About wüstite
Wüstite is a semiconducting iron oxide that exists as a thermodynamically stable phase within the broader family of transition metal conversion oxides. Its unique electronic properties and structural characteristics make it a subject of intense interest for researchers investigating next-generation battery electrode materials.
Because of its ability to undergo conversion reactions, this material is highly relevant for high-capacity energy storage applications. It is widely characterized in literature, with a vast number of reported structural variations that highlight its versatility in electrochemical systems.
Key Properties
Cross-validated computational properties for wüstite, aggregated across 6 databases.
Band GapEnergy needed to move an electron from the valence band to the conduction band. Lower or zero values tend to behave more metallic; larger gaps are more insulating or semiconducting.
Energy Above HullThermodynamic distance from the most stable set of competing phases. 0 eV/atom is on the convex hull; small positive values may still be experimentally accessible.
StabilityA plain-language summary of the best reported energy-above-hull result. It reflects whether the lowest-energy structure is on, near, or far from the stability hull.
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of FeO. Tight agreement means computed properties can be trusted without re-running calculations.
Agreement ScoreA normalized confidence score summarizing how closely independent DFT databases agree. Higher scores mean tighter cross-source agreement.
Hull SpreadDifference between the highest and lowest energy-above-hull values reported by comparable sources. Smaller spread means less thermodynamic disagreement.
Sources ComparedNumber and names of computational sources with comparable entries for this formula.
Space Group ConsensusWhether independent sources predict the same crystal symmetry for the lowest-energy structure.
Reported Structures
Lowest-energy structures reported for FeO, ranked by energy above hull.
| Space GroupSymmetry classification of the crystal arrangement. The number is the international space-group index. | Crystal SystemBroad lattice family, such as cubic, tetragonal, monoclinic, or triclinic, derived from unit-cell symmetry. | Band Gap (eV)Electronic gap calculated for this specific reported structure, measured in electronvolts. | E above hull (eV/atom)Thermodynamic distance from the convex hull for this structure, normalized per atom. Lower is generally more stable. | E/atom (eV)Computed total energy normalized per atom. Use energy above hull, not this value alone, when comparing stability. | Density (g/cm³)Mass per relaxed crystal volume, reported in grams per cubic centimeter. |
|---|---|---|---|---|---|
| C2/m (No. 12) | monoclinic | 2.30 | 0.0000 | -8.191 | 5.61 |
| — | — | 1.59 | 0.0000 | -1.543 | — |
| — | — | 1.18 | 0.0027 | -1.540 | — |
| I4/mmm (No. 139) | tetragonal | 0.00 | 0.0093 | -8.181 | 5.58 |
| C2/m (No. 12) | monoclinic | 0.00 | 0.0120 | -8.178 | 5.60 |
| — | — | 1.08 | 0.0122 | -1.531 | — |
| C2/c (No. 15) | monoclinic | 1.80 | 0.0141 | -8.176 | 5.56 |
| — | — | 1.10 | 0.0190 | -1.524 | — |
| — | — | 1.26 | 0.0244 | -1.519 | — |
| — | — | 1.24 | 0.0245 | -1.519 | — |
| — | — | 0.83 | 0.0345 | -1.508 | — |
| — | — | 1.09 | 0.0377 | -1.505 | — |
Applications
Where wüstite is used.
Patent Landscape
1 patent reference FeO or close compositional variants.
| Patent | Title | Assignee | Granted |
|---|---|---|---|
| 5041409 | Compositions involving FeO-V.sub.2 O.sub.3 -TiO.sub.2 | — | — |
Frequently Asked Questions
Common questions about wüstite, answered from cross-validated data.
What is FeO?
Wüstite is a stable, semiconducting iron oxide utilized primarily as a model material in the study of conversion-type anodes for electrochemical energy storage.
What is FeO used for?
What is the band gap of FeO?
Is FeO a metal, semiconductor, or insulator?
Is FeO thermodynamically stable?
What is the crystal structure of FeO?
What is the density of FeO?
How many polymorphs of FeO are known?
What elements does FeO contain?
Where does the data for FeO come from?
How It Compares
Within the conversion oxide anodes class.
Within the class of conversion oxide anodes, FeO stands out as a fundamental iron-based phase that complements the electrochemical behavior of more complex oxides like Fe3O4 and Fe2O3. While materials such as CuO or MnO2 are often studied for their specific redox potentials, FeO provides a stable, foundational model for understanding the conversion mechanisms common to this entire group of transition metal oxides.
Related Compounds
Other Conversion Oxide Anodes in the database.
Data sources & attribution
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
- oqmd — Data from the OQMD (oqmd.org). Cite: Saal et al., JOM 65, 1501 (2013); Kirklin et al., npj Comp. Mater. 1, 15010 (2015). (CC-BY-4.0)
- jarvis — Data from JARVIS (jarvis.nist.gov), NIST. Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020). (LicenseRef-US-Gov-PD)
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