Chemistry:Potassium fluorosilicate
| Names | |
|---|---|
| Preferred IUPAC name
Potassium fluorosilicate | |
| Other names
Potassium hexafluorosilicate(IV)
| |
| Identifiers | |
3D model (JSmol)
|
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| ChemSpider | |
| EC Number |
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PubChem CID
|
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| RTECS number |
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| UNII | |
| UN number | 2655 |
| |
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| Properties | |
| K 2[SiF 6] | |
| Molar mass | 220.28 g·mol−1 [1] |
| Density | 2.27 g·cm−3,[1] 2.719 g·cm−3 [2] |
| Slightly soluble in water | |
| Structure | |
| cubic | |
| Fm3m | |
a = 0.8134 nm
| |
Lattice volume (V)
|
0.538.2 nm3 |
Formula units (Z)
|
4 |
| Hazards | |
| GHS pictograms | 
|
| GHS Signal word | Danger |
| H301, H311, H331 | |
| P261, P264, P270, P271, P280, P301+310, P302+352, P304+340, P311, P312, P321, P322, P330, P361, P363, P403+233, P405, P501 | |
| Related compounds | |
Other cations
|
Ammonium hexafluorosilicate Sodium fluorosilicate Fluorosilicic acid |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Potassium fluorosilicate is a chemical compound with the chemical formula K
2[SiF
6].
When doped with potassium hexafluoromanganate(IV) (K
2[MnF
6], with Mn4+) it forms a narrow band red producing phosphor, (often abbreviated PSF or KSF), of economic interest due to its applicability in LED lighting and displays.[3][4]
Natural occurrence
Occurs naturally as hiereatite, found in the Aeolian islands (Sicily, Italy).[5] A hexagonal form demartinite has also been found at the rim of volcanic fumaroles in the same islands.[6]
The sea sponge Halichondria Moorei builds a skeleton of potassium fluorosilicate.[7]
Structure and properties
According to analysis by Loehlin (1984), it has space group Fm3m, with a0 = 0.8134 nm, V = 0.538.2 nm3 at 295 K. The Si-F bond length is 0.1683 nm.[2] At high temperatures and pressures -beta and -gamma phases exist.[8]
Applications
Potassium fluorosilicate has applications in porcelain manufacture, the preservation of timber, aluminium and magnesium smelting, and the manufacture of optical glass.[1]
Red phosphor
When doped with potassium hexafluoromanganate(IV) (K
2[MnF
6]), a narrow band red phosphor is produced, emitting at around 630 nm. This substance has application improving the white light quality of white LEDs that use a blue emitting LED in combination with the yellow cerium doped yttrium aluminium garnet phosphor (YAG), Y
3Al
5O
12:Ce3+.[9]
Synthesis routes to the phosphor include co-crystallisation and co-precipitation. For example, K
2[MnF
6] in (40%) hydrofluoric acid with potassium fluoride can be mixed with SiO
2 dissolved in (40%) hydrofluoric acid to co-precipitate the phosphor.[8]
The acronyms KSF or PSF are used for potassium fluorosilicate phosphors.[10]
See also
- Fluorosilicic acid
- Ammonium fluorosilicate
- Sodium fluorosilicate
References
- ↑ 1.0 1.1 1.2 1.3 "44495 Potassium hexafluorosilicate, 99.999 % (metals basis)", www.alfa.com, https://www.alfa.com/en/catalog/044495/
- ↑ 2.0 2.1 Loehlin, J. H. (1984), "Redetermination of the structure of potassium hexafluorosilicate, K2SiF6", Acta Crystallographica C40 (3): 570, doi:10.1107/S0108270184004893, Bibcode: 1984AcCrC..40..570L
- ↑ , Anant Achyut; Robert Joseph Lyons & Prasanth Kumar Nammalwar et al."Moisture-resistant phosphor compositions and associate methods" patent US20160376499A1, issued 2016-12-29
- ↑ , James Edward & Sam Joseph Camardello"Manganese-doped phosphor materials for high power density applications" patent US10615316B2, issued 2020-04-07
- ↑ "Hieratit", www.mineralienatlas.de, https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Hieratit
- ↑ Gramaccioliss, Carlo Maria; Campostrini, Italo (2007), "Demartinite, a new polymorph of K2SiF6 from la Fossa Crater, Vulcano, Aeolian Islands, Italy", The Canadian Mineralogist 45 (5): 1275–1280, doi:10.2113/gscanmin.45.5.1275, Bibcode: 2007CaMin..45.1275G
- ↑ Gregson (30 Nov 1979), "Fluorine is a major constituent of the marine sponge Halochondria Moorei", Science 206 (4422): 1108–1109, doi:10.1126/science.206.4422.1108, PMID 17787487, Bibcode: 1979Sci...206.1108G
- ↑ 8.0 8.1 Verstraete, Reinert; Sijbom, Heleen F.; Joos, Jonas J.; Korthout, Katleen; Poelman, Dirk; Detavernier, Christophe; Smet, Philippe F. (2018), "Red Mn4+-Doped Fluoride Phosphors: Why Purity Matters", ACS Applied Materials & Interfaces 10 (22): 18845–18856, doi:10.1021/acsami.8b01269, PMID 29750494, https://core.ac.uk/download/pdf/158345417.pdf
- ↑ Sijbom, Heleen F.; Verstraete, Reinert; Joos, Jonas J.; Poelman, Dirk; Smet, Philippe F. (1 Sep 2017), "K2SiF6:Mn4+ as a red phosphor for displays and warm-white LEDs: a review of properties and perspectives", Optical Materials Express 7 (9): 3332, doi:10.1364/OME.7.003332, Bibcode: 2017OMExp...7.3332S
- ↑ Happich, Julien (20 Nov 2017), "Differentiate or loose! Yole's analysis on LED phosphors and QDs", www.eenewseurope.com, https://www.eenewseurope.com/news/differentiate-or-loose-yoles-analysis-led-phosphors-and-qds/page/0/1
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