Magnetic Properties of Hot-Pressed

We report on the magnetic properties of a hot-pressed FeSb₂ sample. We find a significant increase in the magnetic susceptibility in our sample when compared with the values previously reported for the polycrystalline sample. The pronounced Curie tail at low temperature corresponds to 0.2% of Fe²⁺ impurities per mole. In the intrinsic conductivity region, the susceptibility due to free carriers shows thermally activated behavior and is consistent with the data reported for single crystal FeSb₂. Based on our data and analysis, while the enhanced magnetic susceptibility in our sample comes mainly from a small amount of unreacted Fe, the contribution from the enhanced carrier density due to lattice and strain defects arising from the ball milling process is also significant. Existence of an unreacted Fe phase is evidenced by small coercivity values of ~100 observed at 50 and 300 K.