[co(nh3)5(no3)](no3)2 as an energetic coordination precursor for the preparation of co3o4 nanoparticles at low temperature

in this paper, an energetic coordination compound namely pentamminenitratocobalt(iii) nitrate, [co(nh3)5(no3)](no3)2, was used as a new precursor for the preparation of co3o4 nanoparticles. the results showed that the complex is easily decomposed into the co3o4 nanoparticles at low temperature (200 °c) without employing a surfactant or solvent and any complicated equipment. the product was characterized by differential scanning calorimetry (dsc), x-ray diffraction (xrd), fourier transform infrared spectroscopy (ft-ir), transmission electron microscopy (tem) and energy-dispersive x-ray spectroscopy (edx). optical and magnetic properties of the product were studied by uv-visible (uv-vis) spectroscopy and a vibrating sample magnetometer (vsm), respectively. ft-ir, xrd and eds analyses confirmed the formation of highly pure spinel-type co3o4 phase with cubic structure. tem images showed that the co3o4 nanoparticles are approximately in the range of 10 to 24 nm with a mean size of around 17 nm. the optical spectrum of the co3o4 nanoparticles revealed the presence of two band gaps at 3.45 and 2.20 ev which are blue-shifted relative to reported values for the bulk sample. the magnetic measurement of the product showed a weak ferromagnetic order at room temperature.