Calcium tungstate

Chemical properties

-325 mesh, 10μm or less 99.9% pure; occurs in nature as mineral scheelite; white tetr powder(s), a=0.524 nm, c=1.138 nm; can be prepared by heating tungstic acid and CaO or CaCO3; used in tumor treatment and in luminous paint [KIR83] [STR93] [MER06]

Large orange octahedral scheelite, Ca(WO4), crystal to 4.5 cm on muscovite, KAl2(AlSi3O10)(OH)2. Pingwu Co., Mianyang pref., Sichuan prov., China.

The Uses of Calcium tungstate

Calcium tungstate can be ued for preparing screens for x-ray observations and photographs; in luminous paints; in scintillation counters.

The Uses of Calcium tungstate

Calcium tungsten oxide is used as a luminophore.

Production Methods

A single crystal is grown from melt by the Czochralski method. Rare earth ions are easy to incorporate into the crystal during growth. Fluorescent films are deposited on a glass substrate through vacuum evaporation using a W filament heated at 2000℃ for about 3 min, followed by thermal annealing in oxygen at 550℃ for 2 h. The film becomes crystalline through this thermal annealing.

What are the applications of Application

Calcium tungstate is well known as the phosphor that emits light in λ: 310–700 nm under the excitation light in λ: 220–300 nm. The peak wavelength is positioned at 440 nm, causing it to give off a blue color.

General Description

Calcium tungstate (CaWO₄) is an optical material, which can be used as a laser host material for a variety of electronic applications. It has a scheelite structure with luminescence, and thermo-luminescence properties.

Structure and conformation

The space lattice of CaWO4 belongs to the tetragonal system, and its Scheelite structure has lattice constants of a=0.524 nm and c=1.138 nm. The space group is I4_1/a, and there are four formula units per unit cell.