Spectroscopic Investigation and Magnetic Study of Iron, Manganese, Copper and Cobalt-doped Hydroxyapatite Nanopowders

Pure, Mn+2, and Fe+3- doped hydroxyapatite (HAp) nanoparticles were synthesized by the wet chemical method. Another two samples were prepared by mixing Mn+2 with Cu+2 into HAp (Mn-Cu HAp) and Fe+3 with Co+2 into HAp (Fe-Co HAp). All samples were prepared without change in the stoichiometric ratio of Ca/P inside the structure of HAp. Samples were characterized by different types of techniques such as XRD, FTIR, ESR, SEM, and EDX. The measurements revealed that a typical HAp powder patterns were obtained. Comparing with pure HAp, Mn+2 substituted HAp (Mn-HAp) and Fe+3 substituted HAp (Fe-HAp) did not demonstrate significant structure deviation. Since the ion exchange mechanism was achieved for the preparation process, the morphology and particle size were not significantly affected but the calculated crystallinity index (CI) values were affected.

The absorption spectra of the doped samples are presented as absorption bands a typical Mn+2, and Fe+3 occupying to different crystalline sites. The obtained data agrees well with that obtained from XRD. The crystal field parameters and crystallinity index for sites of these ions in the HAp matrix were calculated. SEM analysis indicated that nanoparticles aggregates were formed. EPR properties make the studied sample to be used in the field of hyperthermia application.