cr2o3 nanoparticles: synthesis, characterization, and magnetic properties

In this paper, semi-solid precursor of chromium was prepared from the reaction of cr(no3)3 and oxalic acid at the presence of naoh. then cr2o3 nanoparticles were prepared by solid-state thermal decomposition of this precursor at 500 and 600 ºc, at standard atmospheric pressure for 3 h. the as-prepared cr2o3 nanoparticles were characterized by fourier transform infrared (ftir), ultraviolet-visible (uv-vis) spectroscopy, x-ray powder diffraction (xrd), transmission electron microscopy (tem) and vibrating sample magnetometer (vsm). the sharp vibration bands in ft-ir spectra and high intensity peaks in xrd patterns confirmed the preparation of pure, single rhombohedral phase and crystalline eskolaite structure of cr2o3 nanoparticles. a broad absorption peak appeared at uv-vis spectra indicates the d3 electronic transition of cr3+. the tem images show that the particles are similar and a little agglomerated with the average crystal size of < 100 nm. the vsm results predict that the as-prepared cr2o3 nanoparticles are weak ferromagnetic and paramagnetic.