HfO2
Hafnium dioxide · Hafnia
Hafnium dioxide is a chemically stable ceramic material that serves as a high-performance electrical insulator. It is widely utilized in modern electronics due to its ability to function effectively at the microscopic scale within semiconductor devices.
HfO
Overview
Key Properties
Cross-validated computational properties for Hafnium dioxide, 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.
3.39–4.67 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.
0.000 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.
On hull (stable)
3 DFT sources
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
510
5 databases, 56 space groups
Validation
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of HfO2. 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.
1.00 / 1.00
Trust tier: medium
Hull SpreadDifference between the highest and lowest energy-above-hull values reported by comparable sources. Smaller spread means less thermodynamic disagreement.
0.000 eV
EAH spread across sources
Sources ComparedNumber and names of computational sources with comparable entries for this formula.
2
jarvis, materials_project
Space Group ConsensusWhether independent sources predict the same crystal symmetry for the lowest-energy structure.
All match
Crystallography
Reported Structures
Lowest-energy structures reported for HfO2, 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. |
|---|---|---|---|---|---|
| P21/c (No. 14) | monoclinic | 4.02 | 0.0000 | -10.638 | 10.24 |
| Pbca (No. 61) | orthorhombic | 4.11 | 0.0099 | -10.628 | 10.25 |
| Pbca (No. 61) | orthorhombic | 4.23 | 0.0164 | -10.621 | 10.70 |
| Pca21 (No. 29) | orthorhombic | 4.41 | 0.0220 | -10.616 | 10.63 |
| P42/mnm (No. 136) | tetragonal | 3.90 | 0.0370 | -10.601 | 9.41 |
| Pbcn (No. 60) | orthorhombic | 4.26 | 0.0393 | -10.598 | 9.47 |
| P42/nmc (No. 137) | tetragonal | 4.67 | 0.0509 | -10.587 | 10.68 |
| Fm-3m (No. 225) | cubic | 3.80 | 0.0836 | -10.554 | 10.97 |
| P21212 (No. 18) | orthorhombic | 3.75 | 0.0853 | -10.552 | 10.89 |
| Pnma (No. 62) | orthorhombic | 3.39 | 0.1393 | -10.498 | 11.60 |
| P1 (No. 1) | triclinic | 3.62 | 0.2099 | -10.428 | 8.93 |
| P1 (No. 1) | triclinic | 3.40 | 0.2168 | -10.421 | 8.79 |
Uses
Applications
Where Hafnium dioxide is used.
Gate dielectrics in transistorsOptical coatingsHigh-temperature ceramicsDRAM capacitors
Reference
Frequently Asked Questions
Common questions about Hafnium dioxide, answered from cross-validated data.
What is HfO2?
Hafnium dioxide is a chemically stable ceramic material that serves as a high-performance electrical insulator. It is widely utilized in modern electronics due to its ability to function effectively at the microscopic scale within semiconductor devices.
More questions
What is HfO2 used for?
Hafnium dioxide (HfO2) is used in gate dielectrics in transistors, optical coatings, high-temperature ceramics, and dRAM capacitors.
What is the band gap of HfO2?
Hafnium dioxide (HfO2) has a DFT-computed band gap of 3.39–4.67 eV across 510 reported structures.
Is HfO2 a metal, semiconductor, or insulator?
With a wide band gap up to 4.67 eV it is an insulator / wide-band-gap material.
Is HfO2 thermodynamically stable?
Yes — Hafnium dioxide (HfO2) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
What is the crystal structure of HfO2?
The lowest-energy reported polymorph of Hafnium dioxide (HfO2) is monoclinic symmetry, space group P21/c (No. 14).
What is the density of HfO2?
The computed density of the ground-state structure of Hafnium dioxide (HfO2) is 10.24 g/cm³.
How many polymorphs of HfO2 are known?
510 structures of HfO2 are reported across 5 databases, spanning 56 distinct space groups.
What elements does HfO2 contain?
Hafnium dioxide (HfO2) contains Hf and O (2 elements).
Where does the data for HfO2 come from?
HfO2 data is cross-referenced from materials_project, mpaloe.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- mpaloe — Data from mpaloe.
Analyze HfO2 in the Lattice Graph platform
Polymorph comparison, confidence scoring, supply-chain risk, and patent monitoring — across 53 integrated data sources.
Explore the Platform →