Nanorods of silicon carbide from silicon carbide powder by high temperature heat treatment

Nanorods of silicon carbide were found to be produced directly from silicon carbide powder when subjected to high temperature heat treatment. The powder with 20–50 μm grain size was kept in a graphite crucible (enclosed in a chamber/furnace) and heated from its bottom at 2700 °C for 15 min by employing a typical configuration of arc plasma (Ar). The heating was then followed by chamber cooling (up to room temperature) for 2 h. Silicon carbide nanorods of 10–120 nm diameter and 5–20 μm length grew within the powder when the graphite crucible was kept 90% closed at its top end during the heat treatment. The heat treated powder and nanorods were evaluated by XRD, SEM, AFM, HRTEM and micro Raman spectroscopy. A catalyst (Fe) driven two stage VLS mechanism is proposed to understand the growth of the nanorods.