Peltier microcalorimeter

We developed an ac microcalorimeter utilizing the Peltier effect of a therm ocouple junction as an ac power source. This Peltier microcalorimeter allow s us to measure the absolute value of the heat capacity of small samples wi th submilligrams of mass. The performance of the microcalorimeter was check ed in the temperature range of 15-420 K with alpha-Al2O3 samples of 0.54 an d 2.25 mg. The absolute accuracy was +/- 3% for the range of 30-150 K and /- 1% for 150-420 K. The precision was better than 0.5% in the whole temper ature range. (C) 2000 American Institute of Physics. [S0003-6951(00)03917-6 ].