Introduced Another Phase To The Effect Of Cosb₃' Thermoelectric Property

CoSb3 compounds, as a kind of new thermoelectric material, have drawn great attentions owing to large carrier mobility, high electrical conductivity and relatively great Seebeck coefficient. However, high thermal conductivity limits their application. Therefore, it is key problem as to how to significantly decrease the thermal conductivity of CoSb3 compounds with maintaining good electrical transports properties. In this research, another phase was introduced into CoSb3, and study its effects to CoSb3' thermoelectric property, and study the effect of pressure on SPS sintering temperature and thermoelectric property of CoSb3.In this article, Firstly, Al was introduced into CoSb3, and studied its effects to CoSb3' thermoelectric property. Secondly, SPS sintering technics of CoSb3 on higher sintering pressure was investigated, the sintering pressure was 200MPa and the sintering temperature was lower than common technics, then, studied the change of obtained sample's microstructure and thermoelectric property. Finally, SiO2 was introduced into CoSb3, and studied its effects to CoSb3' thermoelectric property.When Al was introduced into CoSb3, the results showed that:electric conductivity decreased evidently, as temperature went up, the degressive range decreased; Seebeck coefficient increased evidently in low temperature range, as temperature went up, the ascending range decreased. When Al content is 0.2wt% or 1wt%, the samples'ZT merit increased in low temperature range, as temperature went up, the ZT merit's ascending range decreased. At 650K, ZT merit began to decrease. When A1 content is 3wt%, the sample's ZT merit decreased.SPS sintering technics of CoSb3 on higher sintering pressure was investigated. The results showed that, all the samples were single-phased CoSb3, the sintering temperature could be decreased evidently, the densities of obtained bulk samples were above 98%. In the same sintering temperature, samples sintered on 200MPa were easier to solve the crackle problem than 300MPa. When the sintering technics was 200MPa,803K and 100MPa,853K, the obtained samples had no crackle. When the sintering technics was 200MPa,803K, compared with common technics, the samples' electric conductivity increased, Seekbeck coefficient decreased, thermal conductivity hardly changed, figure of merit ZT increased. At 303K, the ascending range of ZT was about 17%. When the sintering technics was 100MPa,853K, compared with common technics, the samples'electric conductivity decreased, Seekbeck coefficient increased, thermal conductivity decreased evidently, figure of merit ZT increased evidently. At 473K, the ascending range of ZT was about 34.17%, At 573K, the sample' ZT merit reached 0.184When SiO2 was introduced into CoSb3, the results showed that:electric conductivity decreased evidently, as temperature went up, the degressive range decreased. As SiO2 content increased, the samples'electric conductivity decreased; Seebeck coefficient increased in low temperature range, as temperature went up, the ascending range decreased. As SiO2 content increased, the samples'Seebeck coefficient increased; Thermal conductivity decreased, as temperature went up, the degressive range decreased; ZT merit increased, At low temperature, the increase of ZT was evidently, As SiO2 content increased, the samples'ZT merit increased.