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Potassium niobate

From Wikipedia, the free encyclopedia
Potassium niobate
Names
IUPAC name
Potassium niobate
Other names
niobate, niobium potassium oxide, potassium columbate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.031.573 Edit this at Wikidata
  • 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
Appearance White 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.

Structure

[edit]

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

Applications and research

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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

[edit]

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

References

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  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. ^ a b "In Science Fields". The Science News-Letter. 62 (17): 264–265. 1952-10-25. doi:10.2307/3931381. JSTOR 3931381.
  5. ^ a b 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.