Heat Capacity and Resistivity of Metallic SmS at High Pressure

The heat capacity of SmS has been measured in the metallic and insulating phases between 0.3 and 20 K. The electrical resistivity has been measured between 3 and 298 K in the metallic phase and as a function of pressure at 4.2 and 473 K. The entropy difference shows clearly the demagnetization of the $4f$ electrons in the metallic phase. The electrical resistivity increases with decreasing temperature in the metallic phase. The heat capacity and resistivity of metallic SmS are very similar to those of Sm${\mathrm{B}}_6$, suggesting that the same underlying mechanism is responsible for the unusual properties of both substances.