Cr2O3
Chromium(III) oxide · Chromia, Chromic oxide
Chromium(III) oxide is a stable, semiconducting metal oxide widely used as a catalyst and durable pigment.
About Chromium(III) oxide
Chromium(III) oxide is a robust and thermodynamically stable material that maintains its integrity under a variety of harsh chemical conditions. As a semiconducting oxide, it plays a critical role in facilitating surface-mediated reactions, making it a cornerstone in heterogeneous catalysis and material science research. Its extensive structural documentation across major databases underscores its reliability and importance in fundamental studies.
Beyond its catalytic utility, this compound is highly valued for its chemical inertness and durability. It serves as a primary precursor for various chromium-based materials and is frequently employed in applications requiring high thermal and chemical resistance, such as specialized pigments and protective surface coatings.
Key Properties
Cross-validated computational properties for Chromium(III) oxide, aggregated across 7 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 Cr2O3. 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 Cr2O3, 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. |
|---|---|---|---|---|---|
| — | — | 2.43 | 0.0000 | -2.486 | — |
| R-3c (No. 167) | trigonal | 0.73 | 0.0000 | -2.106 | — |
| R-3c (No. 167) | trigonal | 0.00 | 0.0000 | -9.197 | 5.17 |
| — | — | — | 0.0041 | -2.482 | — |
| — | — | 2.40 | 0.0057 | -2.480 | — |
| Pbcn (No. 60) | orthorhombic | 0.52 | 0.0179 | -2.088 | — |
| — | — | 1.84 | 0.0334 | -2.452 | — |
| Pbcn (No. 60) | orthorhombic | 2.34 | 0.0383 | -9.158 | 5.34 |
| Ia-3 (No. 206) | cubic | 1.78 | 0.0466 | -9.150 | 5.05 |
| — | — | 2.06 | 0.0644 | -2.421 | — |
| — | — | 1.68 | 0.0759 | -2.410 | — |
| R-3 (No. 148) | trigonal | 0.00 | 0.0764 | -9.120 | 4.86 |
Synthesis Routes
Literature-extracted synthesis procedures targeting Cr2O3.
Applications
Where Chromium(III) oxide is used.
Patent Landscape
4 patents reference Cr2O3 or close compositional variants.
| Patent | Title | Assignee | Granted |
|---|---|---|---|
| 6372679 | Cr2O3-Al2O3 sintered body and processes for producing same | — | — |
| 7276226 | Chromium dioxide (CrO2) and composites of chromium dioxide and other oxides of chromium such as CrO2/Cr2O3 and | — | — |
| 6451130 | Method for forming Cr2O3 film on stainless steel surface | — | — |
| 6815386 | Use of phosphates to reduce slag penetration in Cr2O3-based refractories | — | — |
Frequently Asked Questions
Common questions about Chromium(III) oxide, answered from cross-validated data.
What is Cr2O3?
Chromium(III) oxide is a stable, semiconducting metal oxide widely used as a catalyst and durable pigment.
What is Cr2O3 used for?
What is the band gap of Cr2O3?
Is Cr2O3 a metal, semiconductor, or insulator?
Is Cr2O3 thermodynamically stable?
What is the crystal structure of Cr2O3?
How many polymorphs of Cr2O3 are known?
How is Cr2O3 synthesized?
What elements does Cr2O3 contain?
Where does the data for Cr2O3 come from?
How It Compares
Within the group of spinel and transition metal oxides, Cr2O3 stands out for its exceptional thermodynamic stability compared to more reactive counterparts like CuO or NiO. While complex perovskites such as LaMnO3 are often explored for their specific magnetic or electronic tuning, Cr2O3 remains a foundational, high-performance oxide favored for its simplicity and consistent behavior in catalytic environments.
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)
Analyze Cr2O3 in the Lattice Graph platform
Polymorph comparison, confidence scoring, supply-chain risk, and patent monitoring — across 85 source databases.
Explore the Platform →