The analysis of Si doped hydroxyapatite coatings using FIBSEM, TEM and RHEED

Silicon doping has been found to enhance the in vitro and in vivo bioactivity of hydroxyapatite (HA) [1,2], a bioceramic widely used in orthopaedic implants. The atomic arrangement of the Si within the HA structure and the exact role of the dopant on bioactivity are not completely understood [3]. Therefore, the effect of Si dopant levels on the HA thin film structure and chemistry has been examined using the combined techniques of transmission electron microscopy (TEM), selected area electron diffraction (SAED), scanning TEM (STEM), electron energy loss spectroscopy (EELS), energy filtered TEM (EFTEM) and energy dispersive X-ray (EDX) mapping, along with complementary scanning electron microscopy (SEM), X-ray diffraction (XRD) and reflection high energy electron diffraction (RHEED).