Structural and thermoelectric properties of Y1−xB22+yC2−yN Original Research Article

Structural and thermoelectric characteristics for a series of samples Y1−xB22+yC2−yN have been studied. The compound crystallizes with a Y1−xB22C2N-type structure, R-3m space group. The Y1−xB22C2N compound has previously been revealed to exhibit n-type behavior and is potentially the long awaited counterpart of p-type boron carbide. Rietveld refinement revealed a variable boron and carbon composition ranging within 0.08≤y≤0.25 at 0.26≤x≤0.30. The changes in stoichiometry in Y1−xB22+yC2−yN are realized via B/C substitution in one of the C sites of –C–B–C– chains. A small B/C ratio, namely increase of carbon, was revealed to positively affect the thermoelectric properties. The presence of YB28.5C4 as an additive phase was also shown to be beneficial for the thermoelectric properties.