Construction of Constant Pressure Generator and AC calorimetric measurements of Ce_2RhIn_8

它成功地构建了压力高达4 Gpa、温度低至0.75K的恒压发电系统。使其成为可能的重要一点是使用MP30金属作为压杆。这是世界上第一个系统。我们还构建了低温高压交流热能测量系统。为了使交流量热数据的测量成为可能，我们构建了新的点焊系统。在样品上点焊了20μ的Au和Au-Fe0.07细丝热电偶。为了测试该系统，我们测量了CePd_2Si_2和Ce_2RhIn_8的热容。可以清楚地看到，高压下反铁磁有序温度T_N减小了升压，T_N处的跳跃变得更加明显。这一结果表明，该材料在高压下近藤温度升高，磁涨落占主导地位。

It was succeeded in constructing the constant pressure generation system under the pressure up to 4GPa and in the temperature down to 0.75K. The important point to make it possible is using MP30 metal for pressing rod. This is the first system of the world.We have also constructed the ac caloric measurement system for low temperature and high pressure. In order to make it possible to measure ac calorimetric data, we constructed the new spot welding system. It was spot welded 20 μm Au and Au-Fe0.07 thin wire thermocouples on the samples. We have been measured the heat capacity of CePd_2Si_2 and Ce_2RhIn_8 for the test of this measurement system. It is clearly seen that the anti-ferro magnetic ordering temperature T_N decreases increasing pressure and the jump at T_N smears under the high pressure. This result suggests that Kondo temperature increases and magnetic fluctuation is dominated under high pressure in this material.