Calcium deficient hydroxyapatite (CDHA, Ca
10-x
(HPO4
(
x
(PO4
(
6-x
(OH)
2-x
) has attracted many researchers
as natural biocrystals of bone mineral has CDHA structure with Ca/P ratio of about 1.5, which is
chemically and compositionally similar to beta tricalcium phosphate (â-TCP) and structurally similar to
stoichiometric hydroxyapatite (Ca/P = 1.67). Rapid synthesis of CDHA was done by co-precipitation
process of calcium nitrate tetra-hydrate and phosphoric acid and subsequently subjecting the rinsed
precipitate to microwave irradiation in a domestic microwave oven. Transmission electron microscopy
analysis shows needle like morphology of CDHA having length 16-39 nm and width 7-16 nm. The
synthesized CDHA shows characteristic
HPO4
2-
vibration band at 875 cm-1
in Fourier transform infrared (FT-IR) spectra. The additional
confirmation of CDHA by its thermal decomposition to â-TCP was also studied using XRD and FT-IR.
The CDHA was stable up to 600
0
C and transformed to â-TCP at around 650
0
C.
Key words: Calcium deficient hydroxyapatite, nanoparticles, microwave, FT-IR, TEM