Synthesis and optical properties of Mn3O4 nanowires by decomposing MnCO3 nanoparticles in flux

Mn3O4 nanowires with diameters of 30-60 nm and lengths of up to more than 100 mu m were synthesized by decomposing the precursor MnCO3 nanoparticles in NaCl flux. The X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and high-resolution TEM (HRTEM) techniques were used to study structural features and chemical compositions of the prepared nanowires. The Raman optical property of the Mn3O4 nanowires was investigated by Raman spectroscopy, the result indicated that the Raman peak is asymmetric and broadened and is red-shifted 13 cm(-1) compared with that of bulk Mn3O4 crystals. A rational explanation for the red shift and broadening of the Raman peak is discussed in detail according to phonon confinement model of an infinite crystal.