Fluorapatite single crystals

Lapraz D, Gaume F, Barland M (1985) On the thermoluminescent mechanism of a calcium fluorapatite single crystal doped with Mn. Phys Stat Solidi A 89 249-253 Leckebusch R (1979) Comments on the luminescence of apatites from Panasqueria (Portugal). N Jahib Mineral Monat 17-21... 

Morozov A, Morozova L, Trefilov A, FeofilovP (1970) Spectral and luminescent characteristics of fluorapatite single crystals activated by rare earth ions. Opt Spectrosc 29 590-596 Nasdala L, Grambole D, Gotze J et al (2011) Helium irradiation study on zircon. Contrib Miner Petrol 161 777-789... 

Fluorapatite (FA) corresponds to the chemical formula Caio(P04)eF2 and crystallises in the hexagonal space group PGs/m, with Z = 1 and unit-cell parameters a = b = 9.367 A and c = 6.884 A [1] (Fig. 2). From a structural viewpoint, fluorapatite is often considered as a crystalline model for other apatites and is seen as a reference apatitic array [2]. It is one of the very first apatite structures to have been solved. It has been thoroughly studied since the 1930s [3] and is well documented in the literature. In particular, Sudarsanan et al. [1] reported the single crystal refinement of X-ray diffraction (XRD) data, and the detailed description of atomic positions and local symmetry is fully available [4,5],... 

The structure of fluorapatite CajQ(P0 ) F2 was described in the 30 s owing to the existence of well-defined single crystals. 

Figure 12. Separate emission spectra for in the two Ca sites in synthetic single crystal fluorapatite. Generated by taking advantage of the separate excitation bands for the sites shown in Figure 11. Compare with Figure 8. Modified after Ryan et al. (1970).

Zhang XX, Loutts GB, Bass M, Chai BHT (1994) Growth of laser-quahty single crystals of Nd -doped calcium fluorapatite and their efficient lasing performance. Appl Phys Lett 64 10-12... 

The accurate determination of the spatial relationships of ions in a crystal lattice requires that large well-formed single crystals be studied using a variety of techniques including X-ray diffraction, spectroscopic and optical methods. The best apatite crystals for such studies are those of artificially prepared calcium fluorapatite and, the next best, articifically prepared calcium hydroxyapatite. The description which follows is therefore principally of calcium fluorapatite, but the structure of calcium hydroxyapatite will also be mentioned. 

Figure 17. Chondrite-normalized REE patterns for coeval portions of 100 and 001 sectors of a single fluorapatite crystal from the Siglo XX Mine, Llallagna, Bolivia. Sectoral difference in the concentration of La is almost an order of magnitude. [Modified after Rakovan et al. (1997).]...

---