Heat capacity of bulk boron-doped single-crystal HPHT diamonds in the temperature range from 2 to 400 K

Abstract

The heat capacity, C_p, of boron-doped single-crystal diamonds grown by the temperature gradient method was studied. The boron contents were < 10¹⁶, ~ 10¹⁸, and ~ 10²⁰ cm^–3. The heat capacity data for all tested crystals match well (within the measurement accuracy 1%) in the temperature range of 150–400 K and obey the Debye law. At low temperatures the heat capacity follows linear law possibly due to metallic inclusions in diamond bulk. Using this data the amount of metal can be calculated for each sample.