Mn-induced spin glass behavior in metallic Ir₃Sn_7−x Mn _x

Abstract Transition metal stannides are usually semiconductors with a narrow band gap. We report experimental investigation on metallic Ir3Sn7–x Mn x (x = 0 and 0.56). Single crystal x-ray diffraction refinement indicates that Ir3Sn7–x Mn x crystals form a cubic structure (space group Im 3 ̄ m) with the lattice parameter a = 9.362(4) Å for x = 0 and 9.328(6) Å for x = 0.56. The electrical resistivity shows metallic behavior between 2 K and 300 K with T 2 dependence at T < 30 K for x = 0, reflecting the Fermi-liquid ground state. While Ir3Sn7 exhibits weak diamagnetism, partial substitution of Sn by Mn results in spin glass behavior in Ir3Sn7−x Mn x below T g ∼ 13 K for x = 0.56. Remarkably, an upturn in the resistivity is observed in x = 0.56 below ∼2T g, suggesting strong spin fluctuation. This fluctuation is suppressed by the application of magnetic field, which is reflected in the observation of negative magnetoresistance. The unusual properties that emerge due to Mn doping are discussed.