Structure Analysis of A-Type Carbonate Apatite by a Single-Crystal X-Ray Diffraction Method

Diffraction techniques and vibrational spectroscopy opportunities to characterise bones

“…As proposed by Suetsugu et al [23], for the position of CO 3 2− ions (replacing the OH − group) six possibilities around the c-axis are in fact possible for a same chemical composition. In Fig.…”

Infrared spectra of carbonate apatites: ν2-Region bands

“…The structural role of carbonate in hydroxyapatite (HAP) and fluorapatite (FAP) has been investigated extensively by X-ray powder and single-crystal and neutron powder diffraction methods [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22], as well as by infrared (IR, FTIR), Raman and nuclear magnetic resonance (NMR) spectroscopy [23][24][25][26][27][28][29][30][31][32]. It has been established that the carbonate ion can be accommodated either in the c-axis structural channel or as a substituent for the phosphate group: the former carbonate is known as type A and the latter as type B.…”

A new possible atomic arrangement for the carbon atom in the B-sites of AB-type carbonate apatite

“…No vacancy was observed in O1 sites, which exhibit an occupancy factor (O.F.) equal to 1.02 (4). Therefore, we suggested that the CO 3 ions occupy the sites O2 and O3´ of a replaced PO 4 ion, with O.F.…”

“…The refinement in occupancies for the CO 3 and PO 4 ions resulted in ~9.5 wt. (%) of carbonate in this structure.…”

“…As noticed by Fleet and Liu (2003) 3 changes in a (= b) and c unit cell parameters of carbonate apatite (CO 3 -apatite) were observed, comparing with cell parameters of a pure hydroxyapatite. Suetsugu et al 4 analyzed the structure of A-type carbonate apatite with partial occupancy in B sites and observed that a parameter took a middle point of the pure HA and the A-type CO 3 -apatite powder reference, while c parameter was larger in comparison with the pure HA. In our previous work 5 , the X-ray diffraction profile of the AB-type CO 3 -apatite synthetic powder showed a contraction of the a lattice parameter and an enlargement of c lattice parameter.…”