Description
This apatite is formed by the same methods as the
calcium apatite analog. The solid-state reaction required is:
6SrHPO4 + 3SrCO3 + SrF2 + heat?Sr10F2(PO4)6
+ 3CO2 + 3H2O
It has also been prepared by the solution method:
10SrF2 (aq) + 6Na3PO4 (aq)?Sr10(F)2(PO4)6 (solid)
+ 18NaF (aq) + 2HCl
However, the product is contaminated by Na
+ ions
and must be washed thoroughly to obtain a pure product.
A small amount of hydroxyapatite may also be present.
Strontium fluorapatite has been shown to be one of
the best hosts for Nd
3+ doping among apatite crystals.
Neodymium-doped strontium fluorapatite crystal has
been grown by the Czochralski method. The data of
thermal expansion and specific heat of the crystal have
been measured. The thermal expansion coefficients
along X and Z direction are a1 =11.4×10
-6/K and
a3 = 12.3×10
-6/K, respectively. The specific heat is
110 cal/mol K at 330 K. The measured absorption
spectra from 400 to 850 nm showed that the crystal has
absorption peaks around 805.5 nm, and the absorption
coefficients at 805.5 nm are 16.05/cm and 5.59/cm for
p and a-polarization, respectively.
Strontium fluoroapatite does not have a CAS number
even though it is still used as a phosphor for compact
and standard fluorescent lamps. It has been the subject
of numerous academic studies but has found little or
no usage in industry except those already mentioned.
Chemical Properties
fluoroapatite is a mineral for fluorine; can be prepared from CaCl2 and sodium monofluorophosphate; used as a laser crystal(s), may have the lowest energy threshold of any crystal(s) at room temp [KIR78] [HAW93]
Uses
Apatite is one of a few minerals produced and used by biological micro-environmental systems. The primary use of apatite is in the manufacture of fertilizer, it is a source of phosphorus. It is occasionally used as a gemstone. Green and blue varieties in finely divided form, are pigments with excellent covering power.
