Al2FeRh
Al2FeRh is a semimetallic aluminide alloy containing iron and rhodium that serves as a potential candidate for specialized catalytic research.
About Al2FeRh
Al2FeRh is a complex intermetallic compound classified within the platinum-group alloy catalysts. Characterized by a near-zero-gap electronic structure, it functions as a semimetal, which influences its interaction with chemical reactants during surface processes. Its composition balances light aluminum with transition metals to create a unique electronic environment.
This material is considered near-hull in terms of thermodynamic stability, suggesting it is a viable candidate for experimental synthesis and characterization. With multiple reported structures across various databases, it represents a well-documented phase that bridges the gap between traditional noble metal catalysts and more abundant aluminide systems.
Key Properties
Cross-validated computational properties for Al2FeRh, aggregated across 4 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 Al2FeRh. 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 Al2FeRh, 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. |
|---|---|---|---|---|---|
| Fm-3m (No. 225) | cubic | 0.00 | 0.0025 | -0.713 | — |
| Fm-3m (No. 225) | cubic | 0.00 | 0.0114 | -6.528 | 7.13 |
| — | — | 0.00 | 0.0137 | -0.701 | — |
| — | — | 0.00 | 0.0146 | -0.700 | — |
| — | — | 0.00 | 0.3875 | -0.327 | — |
| Immm (No. 71) | orthorhombic | 0.19 | 2.9515 | -3.588 | 0.55 |
| Immm (No. 71) | orthorhombic | 0.02 | 2.9546 | -3.585 | 0.55 |
| Fm-3m (No. 225) | cubic | — | — | — | 7.39 |
| Fm-3m (No. 225) | cubic | — | — | — | 6.92 |
| Fm-3m (No. 225) | cubic | — | — | — | 7.13 |
Applications
Where Al2FeRh is used.
Frequently Asked Questions
Common questions about Al2FeRh, answered from cross-validated data.
What is Al2FeRh?
Al2FeRh is a semimetallic aluminide alloy containing iron and rhodium that serves as a potential candidate for specialized catalytic research.
What is Al2FeRh used for?
What is the band gap of Al2FeRh?
Is Al2FeRh a metal, semiconductor, or insulator?
Is Al2FeRh thermodynamically stable?
What is the crystal structure of Al2FeRh?
How many polymorphs of Al2FeRh are known?
What elements does Al2FeRh contain?
Where does the data for Al2FeRh come from?
How It Compares
Within the platinum-group alloy catalysts class.
Within the diverse family of platinum-group alloy catalysts, Al2FeRh occupies a distinct niche compared to siblings like LaRh or Ga2Ru. While many members of this class are optimized for specific hydrogenation or oxidation pathways, Al2FeRh utilizes its semimetallic nature to offer a different electronic landscape for surface catalysis, distinguishing it from the more conventional metallic behavior found in compounds like BaPd.
Related Compounds
Other Platinum-Group Alloy Catalysts in the database.
Data sources & attribution
- 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)
- 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)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
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