Potassium fluorosilicate
Potassium fluorosilicate is a chemical compound with the chemical formula.
When doped with potassium hexafluoromanganate it forms a narrow band red producing phosphor,, of economic interest due to its applicability in LED lighting and displays.
Natural occurrence
Occurs naturally as hiereatite, found in the Aeolian islands. A hexagonal form demartinite has also been found at the rim of volcanic fumaroles in the same islands.The sea sponge Halichondria Moorei builds a skeleton of potassium fluorosilicate.
Structure and properties
According to analysis by Loehlin, it has space group Fmm, with a0 = 0.8134 nm, V = 0.538.2 nm3 at 295 K. The Si-F bond length is 0.1683 nm. At high temperatures and pressures -beta and -gamma phases exist.Applications
Potassium fluorosilicate has applications in porcelain manufacture, the preservation of timber, aluminium and magnesium smelting, and the manufacture of optical glass.Red phosphor
When doped with potassium hexafluoromanganate, 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,.Synthesis routes to the phosphor include co-crystallisation and co-precipitation. For example, in hydrofluoric acid with potassium fluoride can be mixed with dissolved in hydrofluoric acid to co-precipitate the phosphor.
The acronyms KSF or PSF are used for potassium fluorosilicate phosphors.