Exploring and exploiting the influence of the compression mechanism on the transport properties of CrF3

Abstract

We have explored the influence of the compression mechanism and the temperature on the transport properties of CrF₃. The charge carrier concentration decreases with increasing temperature while it decreases with increasing pressure up to 1.84 GPa; then, after a notable increase in the carrier concentration occurs to reach the maximum value when the pressure rises up to 3.43 GPa, further increases in pressure cause a significant reduction in the carrier concentration to reach the lowest value at 5.43 GPa. Raising the pressure up to 8.56 GPa causes a huge increase in the carrier concentration. An increase in pressure up to 9.12 GPa leads to a drop in the carrier concentration again to the lowest value which was already obtained at 5.43 GPa. Therefore, the pressure value 3.43 GPa is the optimal pressure to gain the highest carrier concentration. It has been found that an electrical conductivity reduction occurs by increasing the temperature within the investigated pressure range. The electrical conductivity significantly increases with increasing pressure, suggesting that the CrF₃ could be a good thermoelectric material. Increasing the temperature within the investigated pressure range causes significant increases (almost linearly) in the Seebeck coefficient. The Seebeck coefficient represents n-/p-type conductions. The electronic thermal conductivity k_e increases linearly with increasing temperature, and at high temperature one can see that increasing the pressure causes a small reduction in k_e. It has been noted that the power factor is zero till 160 K, then above this temperature the power factor increases rapidly with increasing temperature. At high temperatures a reduction in power factor occurs with increasing pressure.