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.

Crystal structure of KNbO3 (trigonal, R3m (No. 160))
Ground-state structure · Materials Project
Overview

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.

At a glance

Key Properties

Cross-validated computational properties for Potassium niobate, aggregated across 6 databases.

Band Gap

1.41–2.29 eV
Range across DFT structures

Energy Above Hull

0.000 eV/atom
Best (lowest) across sources

Stability

On hull (stable)
4 DFT sources

Structures

14
6 databases, 5 space groups
Validation

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 Score

1.00 / 1.00
Trust tier: high

Hull Spread

0.000 eV
EAH spread across sources

Sources Compared

3
jarvis, materials_project, nomad

Space Group Consensus

All match
Crystallography

Reported Structures

Lowest-energy structures reported for KNbO3, ranked by energy above hull.

Space GroupCrystal SystemBand Gap (eV)E above hull (eV/atom)E/atom (eV)Density (g/cm³)
R3m (No. 160)trigonal2.290.0000-8.0674.50
Amm2 (No. 38)orthorhombic2.060.0004-8.0674.50
P4mm (No. 99)tetragonal1.480.0012-8.0664.52
Pm-3m (No. 221)cubic1.410.0077-8.0604.57
Pm-3m (No. 221)
R3m (No. 160)Trigonal4.46
R3m (No. 160)Trigonal4.57
R3m (No. 160)Trigonal4.37
R3m (No. 160)
P4mm (No. 99)
No. 0unknown4.60
Pm-3m (No. 221)
Uses

Applications

Where Potassium niobate is used.

Nonlinear opticsFrequency doublingPiezoelectric sensorsElectro-optic modulatorsHolographic data storage
Reference

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.

More questions
What is KNbO3 used for?
Potassium niobate (KNbO3) is used in nonlinear optics, frequency doubling, piezoelectric sensors, electro-optic modulators, and holographic data storage.
What is the band gap of KNbO3?
Potassium niobate (KNbO3) has a DFT-computed band gap of 1.41–2.29 eV across 14 reported structures.
Is KNbO3 a metal, semiconductor, or insulator?
With a band gap up to 2.29 eV it is a semiconductor.
Is KNbO3 thermodynamically stable?
Yes — Potassium niobate (KNbO3) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
What is the crystal structure of KNbO3?
The lowest-energy reported polymorph of Potassium niobate (KNbO3) is trigonal symmetry, space group R3m (No. 160).
What is the density of KNbO3?
The computed density of the ground-state structure of Potassium niobate (KNbO3) is 4.50 g/cm³.
How many polymorphs of KNbO3 are known?
14 structures of KNbO3 are reported across 6 databases, spanning 5 distinct space groups.
What elements does KNbO3 contain?
Potassium niobate (KNbO3) contains K, Nb, and O (3 elements).
Where does the data for KNbO3 come from?
KNbO3 data is cross-referenced from materials_project, nomad, mpaloe, jarvis, cod, omat24.
Comparison

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.

Explore

Related Compounds

Other Perovskite Oxides in the database.

Data sources & attribution
  • materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
  • nomad — Data from NOMAD. Cite: Draxl & Scheffler, J. Phys. Mater. 2, 036001 (2019).
  • mpaloe — Data from mpaloe.
  • jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).
  • cod — Data from the Crystallography Open Database. Cite: Grazulis et al., Nucleic Acids Res. 40, D420 (2012).
  • omat24 — Data from OMat24 (Meta FAIR). Cite: Barroso-Luque et al., arXiv 2410.12771 (2024).

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