Synthesis of Nano-Fluorohydroxyapatite Thin Film by Sol-Gel Method

Abstract

It is realized that the surface of biomedical metallic implants covered by fluorohydroxyapatite, [Ca10(PO4)6(OH,F)](FHA) can create bioactivity of the implant and shorten healing time. In this work FHA, in the form of powders and of thin films on titanium substrates, were synthesized by sol-gel spin coating method, using calcium nitrate tetrahydrate (Ca(NO3)2.4H2O, phosphorous pentoxide, (P2O5), and ammonium fluoride, (NH4F), to provide calcium precursor, P-precursor and flourine reagent, respectively. The FHA powders were calcined and thin films were fired at temperatures ranging from 500 to 800 centigrade. The constituent of both powders and thin films were confirmed as FHA using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The thermal stability of FHA powders was studied by diffrential thermal analysis (DTA). The optimized calcination and firing temperature was 600 centigrade. Transmission electron microscopy (TEM) results with Debye-Scherrer equation gave the size of FHA particles in nano scale range. The films were found to be quite uniformed and dense by SEM.