FeIr
FeIr is a metallic, metastable alloy of iron and iridium used in the study of advanced platinum-group catalytic materials.
About FeIr
FeIr is a metallic alloy composed of iron and iridium, belonging to the specialized family of platinum-group alloy catalysts. As a metastable phase, it represents a unique structural arrangement that offers distinct chemical reactivity compared to pure elemental catalysts. Its metallic nature ensures high electrical conductivity, making it an intriguing candidate for catalytic processes where electron transfer is critical. The compound is characterized by significant structural diversity, with numerous reported configurations across scientific databases. This structural complexity is a hallmark of its class, reflecting the intricate interplay between the transition metal components that define its potential utility in high-performance catalytic applications.
Key Properties
Cross-validated computational properties for FeIr, 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 FeIr. 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 FeIr, 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. |
|---|---|---|---|---|---|
| — | — | 0.00 | 0.0130 | -0.036 | — |
| — | — | 0.00 | 0.0292 | -0.020 | — |
| — | — | 0.00 | 0.0406 | -0.008 | — |
| R-3m (No. 166) | trigonal | 0.00 | 0.0586 | 0.033 | — |
| R-3m (No. 166) | trigonal | 0.00 | 0.0635 | -8.639 | 15.16 |
| — | — | 0.00 | 0.0854 | 0.037 | — |
| — | — | 0.00 | 0.1083 | 0.059 | — |
| — | — | 0.00 | 0.7779 | 0.729 | — |
| — | — | 0.00 | 1.0094 | 0.961 | — |
| — | — | 0.00 | 1.0297 | 0.981 | — |
| P-1 (No. 2) | triclinic | — | — | — | 20.26 |
| P-1 (No. 2) | triclinic | — | — | — | 10.62 |
Applications
Where FeIr is used.
Frequently Asked Questions
Common questions about FeIr, answered from cross-validated data.
What is FeIr?
FeIr is a metallic, metastable alloy of iron and iridium used in the study of advanced platinum-group catalytic materials.
What is FeIr used for?
What is the band gap of FeIr?
Is FeIr a metal, semiconductor, or insulator?
Is FeIr thermodynamically stable?
How many polymorphs of FeIr are known?
What elements does FeIr contain?
Where does the data for FeIr come from?
How It Compares
Within the platinum-group alloy catalysts class.
Within the diverse group of platinum-group alloys, FeIr occupies a distinct niche compared to compounds like As2Ir or Ga2Ru. While many members of this class exhibit high thermodynamic stability, FeIr is notable for its metastable character, which often provides a higher degree of catalytic activity by allowing for more flexible surface interactions than more inert, highly stable siblings.
Related Compounds
Other Platinum-Group Alloy Catalysts 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)
- jarvis — Data from JARVIS (jarvis.nist.gov), NIST. Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020). (LicenseRef-US-Gov-PD)
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
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