Electrocal, thermal, thermoelectric and related properties of magnesium silicide semiconductor prepared from rice husk

Abstract

Polycrystalline, 10μm size magnesium silicide was prepared by alloying 99.9% purity polycrystalline silicon obtained from rice husk ash and high-purity magnesium powder. The material in sintered pellet form was characterized for its structural, electrical, thermal, thermoelectric and other properties. A typical sintered pellet exhibited a room-temperature (30°C) thermoelectric power of 565 μV K⁻¹ and an electrical resistivity of 35 Ω cm. On the other hand, the material was found to be thermally quite stable up to 650°C with a room-temperature thermal conductivity of 6.3×10⁻³cals⁻¹cm⁻¹K⁻¹ (2.6 J s⁻¹ m⁻¹ K⁻¹). These properties of the material indicate that the material can find potential applications as a thermoelectric generator and in other semiconductor devices. Furthermore, an indigenous technology for large-scale production of silanes (SiH₄) can be developed using this Mg₂Si which could be prepared in large quantities by a simple and low-cost process.