Low-temperature thermo-transport and magnetic properties of HfNiGe alloy

XYZ-type intermetallic compounds exhibit a wide range of intriguing thermophysical properties. Here, we explore the low-temperature thermotransport behavior of a TiNiSi-type intermetallic alloy HfNiGe. The compound was synthesized using a high-temperature arc melting technique from high-purity elements, followed by annealing, pulverizing, and hot-pressing. The x-ray diffraction analysis reveals the presence of an orthorhombic phase belonging to space group pnma. The compound exhibits low electrical resistivity (ρ), increasing from 1 mΩ·cm to 2.5 mΩ·cm with temperature, characteristic of metallic behavior. The thermopower (α) values indicate an n-type system. It increases with temperature up to 150 K, reaching a maximum of ∼ −11 μV·K−1, before declining. The power factor (α2/ρ) attains its highest value of ∼8 μW·m−1·K−2 at 186 K, while the maximum figure-of-merit (zT) of ∼5 × 10−4 is observed at 207 K. Magnetic measurements suggest the presence of short-range ferromagnetic interactions with relatively high coercivity at room temperature. The temperature-dependent magnetic susceptibility (χ), measured under an external field of 50 Oe to 5 kOe, indicates Pauli paramagnetism along with the presence of paramagnetic impurities.