Fe3O4/HAp composite can be used as drug carriers for targeted drug delivery (TTD) applications. Aim of this research was to study the effect of temperature, the mol ratio of Fe3O4/Ca(NO3)2.4H2O, synthesis time of composite Fe3O4/HAp and to calculate the crystal growth of Fe3O4/HAp composite with Avrami equation. Fe3O4 was dissolved with 50 ml aquadest then added 34 mmol Ca(NO3)2.4H2O (100 ml aq…