the magnetite (fe3o4) – agar nanocomposite was prepared by co-precipitation of fe (iii) and fe (ii) ions for the first time. the obtained samples were characterized by x-ray diffraction, fourier-transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. ft-ir results confirm the formation of fe3o4 nanoparticles in agar matrix. the xrd results revealed th...