KNbO3
Potassium niobate · KN
Potassium niobate is a stable, semiconducting perovskite oxide widely utilized for its nonlinear optical and piezoelectric capabilities in high-tech applications.
About Potassium niobate
Potassium niobate is a prominent member of the perovskite oxide family, characterized by its robust thermodynamic stability. As a semiconducting material, it possesses a structural flexibility that allows it to maintain its integrity across various phases, making it a highly studied compound in solid-state chemistry.
Its utility is primarily driven by its exceptional nonlinear optical properties and piezoelectric response. These characteristics enable its integration into advanced optoelectronic devices, where it serves as a critical component for frequency conversion and light modulation technologies.
Key Properties
Cross-validated computational properties for Potassium niobate, aggregated across 6 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 KNbO3. 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 KNbO3, 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. |
|---|---|---|---|---|---|
| R3m (No. 160) | trigonal | 2.31 | 0.0000 | -8.067 | 4.50 |
| R3m (No. 160) | trigonal | 2.09 | 0.0000 | -2.679 | — |
| — | — | 1.71 | 0.0000 | -2.697 | — |
| Amm2 (No. 38) | orthorhombic | 1.89 | 0.0002 | -2.679 | — |
| Amm2 (No. 38) | orthorhombic | 2.06 | 0.0004 | -8.067 | 4.50 |
| P4mm (No. 99) | tetragonal | 1.47 | 0.0012 | -8.066 | 4.52 |
| P4mm (No. 99) | tetragonal | 1.52 | 0.0015 | -2.678 | — |
| — | — | 2.04 | 0.0027 | -2.694 | — |
| — | — | 3.89 | 0.0031 | -2.694 | — |
| — | — | 1.73 | 0.0041 | -2.693 | — |
| — | — | 2.12 | 0.0053 | -2.692 | — |
| Pm-3m (No. 221) | cubic | 1.53 | 0.0059 | -2.673 | — |
Synthesis Routes
Literature-extracted synthesis procedures targeting KNbO3.
Applications
Where Potassium niobate is used.
Frequently Asked Questions
Common questions about Potassium niobate, answered from cross-validated data.
What is KNbO3?
Potassium niobate is a stable, semiconducting perovskite oxide widely utilized for its nonlinear optical and piezoelectric capabilities in high-tech applications.
What is KNbO3 used for?
What is the band gap of KNbO3?
Is KNbO3 a metal, semiconductor, or insulator?
Is KNbO3 thermodynamically stable?
What is the crystal structure of KNbO3?
How many polymorphs of KNbO3 are known?
How is KNbO3 synthesized?
What elements does KNbO3 contain?
Where does the data for KNbO3 come from?
How It Compares
Within the perovskite oxides class.
Within the diverse landscape of perovskite oxides, KNbO3 is distinguished by its strong ferroelectric and nonlinear optical behavior compared to the more metallic or magnetic members of the class, such as LaNiO3 or LaMnO3. While it shares the classic perovskite architecture with materials like BaTiO3 and LaAlO3, its specific electronic character positions it as a specialized functional material rather than a simple dielectric or structural substrate.
Related Compounds
Other Perovskite Oxides in the database.
Data sources & attribution
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (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)
- 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)
- cod — Data from the Crystallography Open Database (crystallography.net/cod/). Cite: Grazulis et al., J. Appl. Cryst. 42, 726 (2009). (CC0-1.0)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
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