Dose response of A-type carbonated apatites prepared under different conditions

Irradiated A-type carbonated apatites with carbonate content ranging from 1 .45% to 4.84% are studied by using electron paramagnetic resonance (EPR). T he EPR spectra are mainly constituted of lines associated to axial CO2- spe cies (g(perpendicular to) = 2.0028 and g(//) = 1.9973) and orthorhombic CO3 - species (g(1) = 2.0170, g(2) = 2.0090 and g(3) = 2.0041). The production of CO2- species on gamma irradiation depends on the carbonate concentration and the hydroxyapatite stoichiometry. The lowest dose detection limit was achieved with stoichiometric samples and carbonate concentration of 3.7%. ( C) 2001 Elsevier Science Ltd. All rights reserved.