Temperature-controlled synthesis of Si3N4 nanomaterials via direct nitridation of Si powders

Si3N4 nanomaterials with different morphologies have been synthesized via direct nitridation of Si powders without using any catalyst by controlling the reaction temperature. The purified Si3N4 samples were characterized by X-ray diffraction and transmission electron microscopy. The results showed that the reaction temperature has an important effect on the crystalline phase and morphology of the Si3N4 samples. The Si3N4 samples undergo a phase transformation of α-Si3N4 to β-Si3N4, and their morphologies change from nanoparticles to nanowires, and then to nanobelts with increase in the reaction temperature.