We report the use of Boltzmann transport theory to investigate the electrical properties of thermoelectric Mg 2 Si, Mg 2 Sn, and a supercell model of the 50-50 alloy. The results are based on first-principles electronic structure calculations with the modified Becke-Johnson potential of Tran and Blaha, which yields band gaps in good accord with experiment. The calculated transport coefficients are discussed in relation to the thermoelectric performance of these materials. The results imply roughly symmetric behavior with respect to carrier type and the possibility of improvements in ZT , especially for p-type and lower temperatures.

No abstract

No abstract

No abstract

No abstract

No abstract

This paper describes a simplified arc discharge method for synthesis of multi-walled carbon nanotubes (MWNTs). In this method, a continuous and mass production of carbon nanotubes (CNTs) can be achieved with high purity and considerable yield. There is no need for costly setup of the synthesis of MWNTs and the multistep purification, which is needed to obtain high pure MWNTs. The morphology and structure of the CNTs produced were characterized by Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X ray diffraction, Raman spectroscopy and Thermo gravimetric analysis (TGA). The cost analysis for the synthesis of MWNTs through this simplified method was done and compared with the existing commercial methods for CNT production. The production cost of the CNTs synthesized by this simplified method is $3/gm. On comparison, it is considered to be one of the most cost effective and commercially viable production methods for MWNTs.

No abstract