Synthesis of β′′-Alumina from Powder Mixture Using Thermal Plasma Processing

Abstract

With the use of a thermal plasma reactor based on the forced constricted type plasma jet generator, the synthesis of thermoelectric materials (β′′-alumina) for the alkali metal thermoelectric converter (AMTEC) has been studied. Under not only atmospheric pressure but also low pressure, thin films of β′′-alumina are successfully synthesized for the first time from powder mixtures of α-Al2O3, Na2CO3 and MgO. The powder mixing ratio, jet power and substrate position strongly affect the synthesis of β′′-alumina, which is found to be correlated with jet temperature.