FeSi2
Iron disilicide · Ferrous disilicide
FeSi2 is a stable semiconducting iron silicide utilized in the development of advanced anode materials and thermoelectric energy systems.
About Iron disilicide
FeSi2 is a semiconducting intermetallic compound that occupies a stable position on the convex hull, indicating robust thermodynamic favorability. Its unique electronic structure makes it a subject of significant interest for researchers developing next-generation energy storage and conversion technologies.
As a member of the silicon anode material class, this compound is valued for its structural integrity and potential to mitigate the challenges associated with silicon-based electrodes. With extensive structural data available across multiple databases, it remains a highly characterized material for high-performance applications.
Key Properties
Cross-validated computational properties for Iron disilicide, aggregated across 5 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 FeSi2. 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 FeSi2, 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. |
|---|---|---|---|---|---|
| — | — | 0.73 | 0.0000 | -0.445 | — |
| Cmce (No. 64) | orthorhombic | 0.70 | 0.0000 | -6.836 | 5.08 |
| P4/mmm (No. 123) | tetragonal | 0.00 | 0.0000 | -0.291 | — |
| — | — | 0.00 | 0.0573 | -0.387 | — |
| P4/mmm (No. 123) | tetragonal | 0.00 | 0.0703 | -6.766 | 5.08 |
| — | — | 0.00 | 0.3205 | -0.124 | — |
| — | — | 0.00 | 0.9521 | 0.508 | — |
| P-1 (No. 2) | triclinic | — | — | — | 2.54 |
| P-1 (No. 2) | triclinic | — | — | — | 5.67 |
| P-1 (No. 2) | triclinic | — | — | — | 5.66 |
| P-1 (No. 2) | triclinic | — | — | — | 4.40 |
| P-1 (No. 2) | triclinic | — | — | — | 5.50 |
Synthesis Routes
Literature-extracted synthesis procedures targeting FeSi2.
Applications
Where Iron disilicide is used.
Patent Landscape
1 patent reference FeSi2 or close compositional variants.
| Patent | Title | Assignee | Granted |
|---|---|---|---|
| 9546801 | Solar-thermal conversion member, solar-thermal conversion device, and solar thermal power generation device co | — | — |
Frequently Asked Questions
Common questions about Iron disilicide, answered from cross-validated data.
What is FeSi2?
FeSi2 is a stable semiconducting iron silicide utilized in the development of advanced anode materials and thermoelectric energy systems.
What is FeSi2 used for?
What is the band gap of FeSi2?
Is FeSi2 a metal, semiconductor, or insulator?
Is FeSi2 thermodynamically stable?
What is the crystal structure of FeSi2?
How many polymorphs of FeSi2 are known?
How is FeSi2 synthesized?
What elements does FeSi2 contain?
Where does the data for FeSi2 come from?
How It Compares
Within the silicon anode materials class.
Within the broader family of silicon-based materials, FeSi2 distinguishes itself from more common elemental silicon or simple silicides like Mg2Si and NaSi by its specific semiconducting properties and thermodynamic stability. While materials like MoSi2 are often favored for high-temperature structural applications, FeSi2 is frequently studied for its distinct electronic behavior and potential in integrated silicon-based devices.
Related Compounds
Other Silicon Anode Materials in the database.
Data sources & attribution
- 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)
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (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)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
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