Structure and Thermal Stability of Lithium-Substituted Hydroxyapatite Ceramics

-We have studied the effect of doping with lithium cations on the phase composition, lattice parameters, and crystallite size of hydroxyapatite at different heat treatment temperatures (900, 1200, and 1400 degrees C). The results demonstrate that, at high degrees of substitution (20 mol %) and heat treatment temperatures of 1200 and 1400 degrees C, lithium cations contribute to conversion of apatite into lithium-substituted tricalcium phosphate. At degrees of substitution of 1, 5, and 10 mol %, the addition of lithium causes no destabilization of the apatite structure even at a temperature of 1400 degrees C.