IrOs
IrOs is a metastable metallic alloy of iridium and osmium used primarily in fundamental catalytic research.
About IrOs
IrOs is a metallic binary alloy composed of iridium and osmium, belonging to the class of platinum-group metal systems. As a metastable phase, it represents a specialized material configuration that is of significant interest for fundamental studies in solid-state chemistry and materials science.
Its metallic nature makes it a subject of investigation for catalytic applications where electron mobility and surface reactivity are critical. The compound is supported by a substantial body of structural data, reflecting its importance in understanding the complex phase behavior of heavy transition metal alloys.
Key Properties
Cross-validated computational properties for IrOs, 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 IrOs. 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 IrOs, 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. |
|---|---|---|---|---|---|
| P-6m2 (No. 187) | hexagonal | 0.00 | 0.0210 | 0.016 | — |
| — | — | 0.00 | 0.0304 | 0.029 | — |
| P-6m2 (No. 187) | hexagonal | 0.00 | 0.0384 | -52.634 | 22.34 |
| — | — | 0.00 | 0.0499 | 0.048 | — |
| — | — | 0.00 | 0.2035 | 0.202 | — |
| — | — | 0.00 | 0.7879 | 0.786 | — |
| — | — | 0.00 | 1.0864 | 1.085 | — |
| — | — | 0.00 | 1.3073 | 1.306 | — |
| P1 (No. 1) | triclinic | — | — | — | 22.24 |
| P-1 (No. 2) | triclinic | — | — | — | 18.05 |
| P1 (No. 1) | triclinic | — | — | — | 19.77 |
| P1 (No. 1) | triclinic | — | — | — | 25.33 |
Applications
Where IrOs is used.
Frequently Asked Questions
Common questions about IrOs, answered from cross-validated data.
What is IrOs?
IrOs is a metastable metallic alloy of iridium and osmium used primarily in fundamental catalytic research.
What is IrOs used for?
What is the band gap of IrOs?
Is IrOs a metal, semiconductor, or insulator?
Is IrOs thermodynamically stable?
What is the crystal structure of IrOs?
How many polymorphs of IrOs are known?
What elements does IrOs contain?
Where does the data for IrOs come from?
How It Compares
Within the platinum-group alloy catalysts class.
Within the diverse landscape of platinum-group alloys like As2Ir and GeRu, IrOs stands out as a simple binary metallic system that highlights the structural variety possible between heavy transition metals. While many of its siblings exhibit complex stoichiometry or non-metallic character, IrOs maintains a straightforward metallic profile that provides a baseline for comparing the catalytic efficiency and phase stability of iridium-osmium systems against more complex intermetallics.
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)
- 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)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
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