Synthesis and Orientation of Fe-doped Hydroxyapatite in High Magnetic Field

The surface nanostructure of bioceramics can affect osteoblast proliferation and differentiation, therefore the control of the surface microstructure of bioceramics, especially grain orientation before the ceramic sintering, is one of key to design and develop bioactive ceramics for bone regeneration.This study aimed to investigate the crystal orientation of Fe-doped hydroxyapatite in high magnetic field.Pure hydroxyapatite (HA) and Fe-doped hydroxyapatite (Fe-HA) powders were prepared by co-precipitation method and co-precipitation-hydrothermal method, and their phase composition, microstructure, magnetic property, and elementary composition were analyzed by XRD, SEM, TEM, PPMS, and ICP.The results showed that the phase of Fe-HA is the same as HA with no impurity phase.HA is diamagnetic originally, while Fe-HA becomes paramagnetic.The microstructure of samples prepared by co-precipitation method is needle cluster-like but that prepared by co-precipitation-hydrothermal method is rod-like.It is the rad-like but not the needle cluster-like Fe-HA can be orientated in high magnetic field.Therefore, the orientation of rod-like Fe-HA can be regulated by high magnetic field.Furthermore, pure HA cannot be uniaxial orientated in single-directed high magnetic field.while Fe-HA can be oriented along c axis in certain degree in singledirected high magnetic field.