Potassium fluorosilicate

Occurs naturally as hiereatite, found in the Aeolian islands (Sicily, Italy). 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 (1984), 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(IV) ), 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), . Synthesis routes to the phosphor include co-crystallisation and co-precipitation. For example, in (40%) hydrofluoric acid with potassium fluoride can be mixed with dissolved in (40%) hydrofluoric acid to co-precipitate the phosphor. The acronyms KSF or PSF are used for potassium fluorosilicate phosphors. == See also ==