Silicon hexaboride shows some conflicting property measurements in the literature, with some which suggest it may have the potential of operation with thermoelectric figures of merit of 1 X 10-3 IC I well above 725 'C. To remove the confusion, it is planned to make material of very high purity, in crystal sizes as large as possible so as to ensure maximum accuracy of property measurements. The material will be carefully characterized so as to establish its real potential. In Phase I only p-type material will be considered. In Phase II producing n-type material will be attempted as well.Anticipated Results/Potential Commercial Applications as described by the awardee:Space power systems would become much more competitive if the energy conversion efficiency of radioisotope thermoelectric generators could be raised above the levels currently achievable with silicon germanium. Commercial applications of space are growing rapidly. Silicon hexaboride has many other materials applications tied into its light weight, high hardness, and refractory properties, ranging from armor applications to machine cutting tools.
