Microstructure and Properties of Biogenic Hydroxyapatite Doped with Magnetite

In this study the hydroxyapatite powder was sintered together with magnetite nanopowder, which due to its low reactivity is commonly used in medicine, eg. in magnetic resonance. Two types of sintered materials, containing equal content 6 mol% of biogenic hydroxyapatite (BGHAp), reinforced with 50 wt% of different glass phases, were tested. The same technological conditions comprising two-stage sintering with T1 (1100ºC) and T2 (780ºC) were used for both types of materials. For selected specimens 2 wt% of 9 nm powder of Fe3O4 was added. The microhardness of the specimens varies within quite wide range from 150 to 508 HV0.025. Compressive splitting strength of the specimens (measured along the sample diameter) is within a range of 3.61 – 4.99 MPa. Young’s modulus, modulus of rigidity and Poisson’s ratio are in the ranges of: 20.81 – 24.86 GPa, 7.89 – 9.71 GPa and 0.252 – 0.307, respectively. Indentation fracture toughness KIC is within a range of 0.6-1.0 MPa m1/2. The hysteresis loops were determined in order to asses the possibility of application of this material as affecting the drug delivery carriers. The specimens exhibit magnetization of the order of 1.5 emu/g.