PREPARATION AND THERMOELECTRIC PROPERTIES OF IRXCO1-XSB2 ALLOYS

The preparation and characterization of the binary arsenopyrite compou nds CoSb2 and IrSb2 and IrxCo1-xSb2 alloys is reported. Single crystal s of CoSb2 were grown by the vertical gradient-freeze technique from s olutions rich in antimony. Polycrystalline samples of IrSb2 and IrxCo1 -xSb2 alloys were prepared by hot-pressing of prereacted elemental pow ders. Samples were investigated by X-ray diffractometry, microprobe an alysis and density measurements. It was found that a range of solid so lutions exists in the system IrxCo1-xSb2. Samples were also characteri zed by high temperature electrical resistivity, Seebeck coefficient an d thermal conductivity measurements. All materials have p-type conduct ivity and are semiconductors. A band gap of about 0.98 eV was calculat ed for IrSb2. Preliminary measurements of the thermoelectric propertie s of these materials showed that their potential for thermoelectric ap plications is limited.