Potassium niobate

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Potassium niobate
Cubic perovskite structure.png
Names
IUPAC name
Potassium niobate
Other names
niobate, niobium potassium oxide, potassium columbate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.031.573 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
  • InChI=1S/K.Nb.3O/q+1;;;;-1
    Key: UKDIAJWKFXFVFG-UHFFFAOYSA-N
  • [O-] [Nb](=O)=O.[K+]
Properties
KNbO3
Molar mass 180.003 g·mol−1
AppearanceWhite rhombohedral crystals
Density 4.640 g/cm3
Melting point ≈ 1100 °C [1]
Hazards
Lethal dose or concentration (LD, LC):
3000 mg/kg (oral, rat)
Related compounds
Other anions
Potassium chlorate
Potassium bromate
Other cations
Lithium niobate
Strontium barium niobate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Potassium niobate (KNbO3) is an inorganic compound with the formula KNbO3. A colorless solid, it is classified as a perovskite ferroelectric material. [2] It exhibits nonlinear optical properties, and is a component of some lasers. [3] Nanowires of potassium niobate have been used to produce tunable coherent light.

Contents

Structure

On cooling from high temperature, KNbO3 undergoes a series of structural phase transitions. At 435 °C, the crystal symmetry changes from cubic centrosymmetric (Pm3m) to tetragonal non-centrosymmetric (P4mm). On further cooling, at 225 °C the crystal symmetry changes from tetragonal (P4mm) to orthorhombic (Amm2) and at −50 °C from orthorhombic (Amm2) to rhombohedral (R3m).

Crystal structure of Potassium Niobate KNbO3.tif
Crystal structure of Potassium Niobate

Applications and research

In addition to research in electronic memory storage, [4] potassium niobate is used in resonant doubling. [5] This technique allows small infrared lasers to convert output into blue light, a critical technology for the production of blue lasers and technology dependent upon them.

Potassium niobate has been found useful in many different areas of materials science, [4] including properties of lasers, [5] quantum teleportation, [6] and it has been used to study the optical properties of particulate composite materials. [7]

Safety

The LD50 for potassium niobate is 3000 mg/kg (oral, rat).

References

  1. ↑ CRC Handbook, 90th Edition (03 Jun 2009) ISBN   1-4200-9084-4, section 4: Physical Constants of Inorganic Compounds, page 83
  2. ↑ Hewat, A W (1973-03-28). "Soft modes and the structure, spontaneous polarization and Curie constants of perovskite ferroelectrics: tetragonal potassium niobate" . Journal of Physics C: Solid State Physics. 6 (6): 1074–1084. Bibcode:1973JPhC....6.1074H. doi:10.1088/0022-3719/6/6/020. ISSN   0022-3719.
  3. ↑ Palik, Edward D. (1998). Handbook of Optical Constants of Solids 3. Academic Press. p. 821. ISBN   978-0-12-544423-1 . Retrieved 13 December 2012.
  4. 1 2 "In Science Fields". The Science News-Letter. 62 (17): 264–265. 1952-10-25. doi:10.2307/3931381. JSTOR   3931381.
  5. 1 2 Regalado, Antonio (1995-03-31). "Blue-Light Special". Science. New Series. 267 (5206): 1920. Bibcode:1995Sci...267.1920R. doi:10.1126/science.267.5206.1920. JSTOR   2886437. PMID   17770099.
  6. ↑ Furusawa, A.; J. L. Sørensen; S. L. Braunstein; C. A. Fuchs; H. J. Kimble; E. S. Polzik (1998-10-23). "Unconditional Quantum Teleportation". Science. New Series. 282 (5389): 706–709. Bibcode:1998Sci...282..706F. doi:10.1126/science.282.5389.706. JSTOR   2899257. PMID   9784123.
  7. ↑ Lakhtakia, Akhlesh; Tom G. Mackay (2007-02-08). "Electrical Control of the Linear Optical Properties of Particulate Composite Materials". Proceedings of the Royal Society A. 463 (2078): 583–592. arXiv: physics/0607274 . Bibcode:2007RSPSA.463..583L. doi:10.1098/rspa.2006.1783. JSTOR   20209136. S2CID   119419605.
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