- Research was conducted to determine the thermoelectric behavior of Co₉S₈, Co₉Se₈,
CoSe, CoTe₂, CoSbSexSl-x (x=O, 0.25, 0.50, 0.75, 1.0), CoSbTe, AuTe₂, AuTe₁.₉₀Sb₀.₁₀,
Au₀.₉₅Pt₀.₀₅Te₂, Au₀.₉₅Ag₀.₀₅Te₂, MnTe₂, MnTe₁.₉₅Sb₀.₀₅, MnTe₁.₉₀Sb₀.₁₀, CoSb₂, and Co₀.₉₅Fe₀.₀₅Sb₂. Recently discovered sodium cobalt oxide compounds have been found to
have large Seebeck coefficients coupled with favorable thermal and electrical resistivity,
making them promising candidates for future thermoelectric device applications.
Research suggests that this behavior in the sodium cobalt oxides is due to the 4 +
oxidation state of cobalt atoms within these materials. Cobalt compounds can in some
cases retain large amounts of entropy until low temperature magnetic ordering of
electrons occurs within the compound. The electrical resistivity and thermal resistivity of
these cobalt compounds become more favorable at these lower temperatures. In these
compounds, a consistently high Seebeck coefficient is maintained until the rapid low
temperature magnetic ordering occurs. Additional non-cobalt-containing compounds
were also tested based upon their promise as future thermoelectric materials. The
Seebeck coefficient, magnetic susceptibility, electrical resistivity, and structural
properties of selected compounds were observed and recorded.
- Key Words: Thermoelectric, Cobalt, Manganese, Conductivity, Resistivity, Seebeck