CaHfO3
calcium hafnate · calcium hafnium oxide
Calcium hafnate is a stable, insulating oxide material utilized in high-performance dielectric and refractory technologies.
About calcium hafnate
Calcium hafnate is a thermodynamically stable inorganic compound that functions as a wide-band-gap insulator. Its robust structural integrity and electronic properties make it a subject of significant interest for high-performance dielectric and thermal barrier applications.
As a member of the fluorite-related oxide family, this material is valued for its chemical stability in demanding environments. It is frequently investigated for its potential in microelectronics and as a specialized refractory component where insulating performance is critical.
Key Properties
Cross-validated computational properties for calcium hafnate, 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 CaHfO3. 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 CaHfO3, 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. |
|---|---|---|---|---|---|
| — | — | 4.72 | 0.0000 | -3.669 | — |
| Pnma (No. 62) | orthorhombic | 4.57 | 0.0000 | -3.679 | — |
| Pnma (No. 62) | orthorhombic | 4.49 | 0.0000 | -9.182 | 7.02 |
| — | — | 5.34 | 0.0190 | -3.650 | — |
| — | — | 4.28 | 0.0210 | -3.648 | — |
| — | — | 4.29 | 0.0276 | -3.641 | — |
| — | — | 4.27 | 0.0601 | -3.609 | — |
| — | — | 3.76 | 0.0641 | -3.605 | — |
| — | — | 3.98 | 0.1168 | -3.552 | — |
| — | — | 3.91 | 0.1586 | -3.510 | — |
| Pm-3m (No. 221) | cubic | 3.66 | 0.1601 | -9.022 | 6.58 |
| — | — | 3.84 | 0.1602 | -3.509 | — |
Synthesis Routes
Literature-extracted synthesis procedures targeting CaHfO3.
Applications
Where calcium hafnate is used.
Frequently Asked Questions
Common questions about calcium hafnate, answered from cross-validated data.
What is CaHfO3?
Calcium hafnate is a stable, insulating oxide material utilized in high-performance dielectric and refractory technologies.
What is CaHfO3 used for?
What is the band gap of CaHfO3?
Is CaHfO3 a metal, semiconductor, or insulator?
Is CaHfO3 thermodynamically stable?
What is the crystal structure of CaHfO3?
How many polymorphs of CaHfO3 are known?
How is CaHfO3 synthesized?
What elements does CaHfO3 contain?
Where does the data for CaHfO3 come from?
How It Compares
Within the fluorite oxide-ion conductors class.
Within the diverse group of fluorite-related oxide-ion conductors, calcium hafnate stands out as a highly stable insulating counterpart to more conductive or defect-rich members like Y2Zr2O7 or La2Zr2O7. While many siblings in this class are engineered specifically for ionic transport, CaHfO3 is primarily recognized for its structural resilience and dielectric utility, distinguishing it from the pyrochlore-structured zirconates.
Related Compounds
Other Fluorite Oxide-Ion Conductors 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.
- alexandria — Data from Alexandria. Cite: Schmidt et al., npj Comput. Mater. 10, 200 (2024). (CC-BY-4.0)
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