Effect of the Substitution of Zinc on the Microstructure of β-Tricalcium Phosphate

X-ray diffraction and infrared absorption analysis were carried out on zinc-doped beta-tricalcium phosphate prepared by a liquid-phase reaction technique. Quantitative methods and regression analysis were used to calculate the variation of lattice constants of TCP, and the shift or degeneracy of the PO43- infrared absorption bands. X-ray diffraction analysis indicates that zinc can substitute calcium up to 20 atom %, inducing a statistically significant decrease of the lattice constants a and b. As the zinc content in TCP increases beyond 20 atom %, X-ray diffraction analysis shows the appearance of a new phase α-CaZn2(P04)2. However, the effect of substitution of zinc on the lattice constant c is abnormal. The substitution of Zn up to 10 atom % results in a general decrease of the lattice constants c, while it increases as the content of zinc in TCP increases beyond 10%. FTIR spectra reveal that the substitution of Zn up to 10 atom% results in a statistically significant increase of the asymmetric P-O stretching vibration absorption band at 1045 and 1120cm-1 (P 0.05) and a statistically significant decrease of O-P-O bending vibration absorption band at 605cm-1 (P=0.00085), respectively.