Grain Boundary Engineering of Thermoelectrics for RTGs

This proposed research plans to analyze and exploit the influence of grain boundaries on the thermal and electrical conductivity of the high temperature thermoelectric materials Yb14MnSb11 and La3Te4 to boost RTG efficiency. Recent work on the thermoelectric material Mg2Sb3 has shown a more than two-fold improvement in thermoelectric figure of merit at low temperatures while still improving high temperature properties through grain boundary engineering and the tailoring of processing conditions. This approach will be applied to these high temperature RTG materials in conjunction with long term stability testing to ensure reliable performance in typical RTG operating conditions.