Experimental set-up for thermopower measurement under high pressure using "seesaw heating method"

We have developed a set-up with modified "seesaw heating method" for the simultaneous measurement of thermopower S and electrical resistivity р under hydrostatic pressures P up to 3 GPa at the temperature range between 1.5 K and 300 K. By using this set-up, S and р of single crystalline YbMn_2Ge_2 and EuCo_2P_2 under high pressure were measured with enough accuracy. The temperature dependences of S and р show drastic changes at the critical pressure P_c in both compounds. The measurement results indicate that the simultaneous measurement of S and р is a usuful tool to study the pressure-induced phase transitions