Na2FeO2
Sodium ferrate is an inorganic compound containing iron in a formal oxidation state. It is primarily studied for its potential role as a cathode material in advanced battery technologies.
Overview
Key Properties
Cross-validated computational properties for Na2FeO2, aggregated across 3 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.
0.04–1.26 eV
Range across DFT structures
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.
0.053 eV/atom
Best (lowest) across sources
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.
Metastable
2 DFT sources
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
16
3 databases, 5 space groups
Crystallography
Reported Structures
Lowest-energy structures reported for Na2FeO2, 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. |
|---|---|---|---|---|---|
| Immm (No. 71) | orthorhombic | 0.00 | 0.0532 | -5.745 | 3.32 |
| Cmc21 (No. 36) | orthorhombic | 0.04 | 0.0715 | -5.727 | 3.28 |
| P21/c (No. 14) | monoclinic | 0.83 | 0.0866 | -5.711 | 3.16 |
| Pbcn (No. 60) | orthorhombic | 1.26 | 0.1065 | -5.691 | 2.71 |
| Cmc21 (No. 36) | — | — | — | — | — |
| Immm (No. 71) | Orthorhombic | — | — | — | 3.11 |
| P21/c (No. 14) | Monoclinic | — | — | — | 3.37 |
| Immm (No. 71) | Orthorhombic | — | — | — | 3.33 |
| Cmc21 (No. 36) | Orthorhombic | — | — | — | 3.28 |
| P-1 (No. 2) | — | — | — | — | — |
| P21/c (No. 14) | Monoclinic | — | — | — | 3.16 |
| Immm (No. 71) | — | — | — | — | — |
Uses
Applications
Where Na2FeO2 is used.
Battery researchElectrochemical energy storage
Reference
Frequently Asked Questions
Common questions about Na2FeO2, answered from cross-validated data.
What is Na2FeO2?
Sodium ferrate is an inorganic compound containing iron in a formal oxidation state. It is primarily studied for its potential role as a cathode material in advanced battery technologies.
More questions
What is Na2FeO2 used for?
Na2FeO2 is used in battery research and electrochemical energy storage.
What is the band gap of Na2FeO2?
Na2FeO2 has a DFT-computed band gap of 0.04–1.26 eV across 16 reported structures.
Is Na2FeO2 a metal, semiconductor, or insulator?
With a band gap up to 1.26 eV it is a semiconductor.
Is Na2FeO2 thermodynamically stable?
Na2FeO2 has a lowest energy above hull of 0.053 eV/atom (metastable).
What is the crystal structure of Na2FeO2?
The lowest-energy reported polymorph of Na2FeO2 is orthorhombic symmetry, space group Immm (No. 71).
What is the density of Na2FeO2?
The computed density of the ground-state structure of Na2FeO2 is 3.32 g/cm³.
How many polymorphs of Na2FeO2 are known?
16 structures of Na2FeO2 are reported across 3 databases, spanning 5 distinct space groups.
What elements does Na2FeO2 contain?
Na2FeO2 contains Fe, Na, and O (3 elements).
Where does the data for Na2FeO2 come from?
Na2FeO2 data is cross-referenced from materials_project, jarvis, mpaloe.
Explore
Related Compounds
Other Layered Sodium Transition-Metal Oxides in the database.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).
- mpaloe — Data from mpaloe.
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