Hydrothermal Synthesis and Crystallographic Study of Sr-Pb Hydroxyapatite Solid Solutions

Abstract

A continuous series of solid solutions in the system of strontium and lead hydroxyapatite, Pb_xSr_1-xHAP (x=0-1), was successfully synthesized by low-temperature mixing method (LTMM) at 160°C for 12 h under hydrothermal conditions. The samples were characterized by chemical analysis, electron microscopic observation and X-ray powder-pattern fitting. The site of the metal ions in the solid solutions was analyzed by the Rietveld method. The lattice constants of the prepared solid solutions varied linearly with Pb contents. It was found that Pb²⁺ ions in the solid solutions preferentially occupied the M(2) site in the apatite structure.