Development of valid thermoelectaic element in the low temperature region

As a result of searching of material indicating enormous thermoelectric power, CeNi_9Si_4 was found as positive thermoelectric element. Pertie effect was measured using thermoelectric element with CeNi_9Si_4 and YbCu_<4.5>Ag_<0.5> at room temperature and 77K. Peritie coefficient Π=3.49 mV, thermoelectric power S=12μV/K and the dimensionless figure merit ZT=1.46X10<^-4> were obtained at room temperature. At 77 K, pertie coefficient Π=4.57 mV, thermoelectric power S=59.4 V/K and ZT=1.26X10^<-3> were observed. This dimensionless figure merit ZT=1.26X10^<-3> at 77 K is one order of magnitude larger than that of room temperature's and of CePd_2Al_3-YbCu_<4.5>Ag_<0.5> thermoelectric element. In order to small thermal conductivity, I have reduced the two samples, CeNi_9Si_4 and YbCu_<4.5>Ag_<0.5>, to powder. Two powder samples of CeNi_9Si_4 and YbCu_<4.5>Ag_<0.5> were made to press as much as 200 kg/cm^2. The ZT, however, was obtained smaller value than the former element. The origin of bad result was thought to be lack of the pressure. As a result, it was found that CeNi_9Si_4-YbCu_<4.5>Ag_<0.5> element was valid for low temperatures region at the present time.