Effects of Sintering Temperature and Method on the Thermoelectric Properties of MgAlB14

Boron-rich thermoelectric materials have been reported to have a large Seebeck coefficient and low heat conductivity and are advantageous for its power generation efficiency. However, achieving high electrical conductivity is necessary for boron-rich thermoelectric materials to be used practically in wide range of application. The materials with high thermoelectric performance are produced by pressure sintering methods like Spark Plasma Sintering (SPS). Therefore, low productivity is another issue to overcome.We investigated microstructure and thermoelectric performance of MgAlB14-base sintered bodies prepared by SPS and atmosphere sintering. The samples contain a by-product, MgAl2O4, and a material prepared by atmosphere sintering exhibited a high Seebeck coefficient more than 350 μV/K at 400-600°C, that indicated the atmosphere sintering can produce MgAlB14-base thermoelectric materials of a high Seebeck coefficient with higher productivity.