Mn-induced spin glass behavior in metallic Ir3Sn7- xMnx

Abstract

Transition metal stannides are usually semiconductors with a narrow band gap. We report experimental investigation on metallic Ir₃Sn_7-xMn_x(x= 0 and 0.56). Single crystal x-ray diffraction refinement indicates that Ir₃Sn_7-xMn_xcrystals form a cubic structure (space groupIm3̄m) with the lattice parametera= 9.362(4) Å forx= 0 and 9.328(6) Å forx= 0.56. The electrical resistivity shows metallic behavior between 2 K and 300 K withT²dependence atT< 30 K forx= 0, reflecting the Fermi-liquid ground state. While Ir₃Sn₇exhibits weak diamagnetism, partial substitution of Sn by Mn results in spin glass behavior in Ir₃Sn_7-xMn_xbelowT_g∼ 13 K forx= 0.56. Remarkably, an upturn in the resistivity is observed inx= 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.

Keywords: Ir3Sn7 − x Mn x; Mn doping; electrical resistivity; magnetoresistance; spin glass.