Formation of nano CoFe2O4 crystallites in hydroxyapatite

Abstract

Embedding nano size CoFe2O4 ferrite particles in a hydroxyapatite (HAP) host would make them to better candidates for hyperthermia treatment of cancer. The formation of nano crystallites of CoFe 2O4 ferrites in the hydroxyapatite Ca 10-3xFe2xCox(PO4) 6(OH)2 where x= 0-0.5 %mole mixtures heated to temperatures between 500 and 1250°C for 2 hrs were monitored by several techniques. The DSC/TGA scan shows that the crystallization occurs at 731°C. The developments of peaks in the XRD patterns and of new vibration modes in the FT-IR spectrums of the Fe3+/Co2+ doped hydroxyapatite (HAP) compounds heated above 750°C indicate the formation of CoFe 2O4 nano crystallites inside the HAP lattice. ESR measurements show the Co2+ ions substituting into the Ca(1) sites in HAP lattice when the HAP is heated above 750°C. SEM show that crystallites of irregular shapes coalesced into larger aggregates of cubic symmetrical structure characteristic of CoFe2O4 spinel as the annealing temperature is increased.