Large magnetoresistance and quantum oscillations observed in superconducting β -IrSn 4

Abstract Diverse quantum phenomena have been observed in TSn 4 transition metal ( T ) stannides, including superconductivity, nontrivial topology, and large magnetoresistance (MR) at low temperatures. Here, we report the experimental and theoretical investigation of tetragonal β -IrSn 4 (space group I 4 1 / acd ) with the lattice parameters a = 6.362(3) Å and c = 22.723(0) Å. The temperature dependence of the electrical resistivity indicates that β -IrSn 4 is a good metal with Fermi-liquid behavior above the superconducting transition at T c ∼ 0.7 K. Magnetic susceptibility measurements indicate it is non-magnetic. However, positive transverse MR with linear field dependence is observed. At T = 2 K and Μ 0 H = 14 T, the MR reaches 700% without sign of saturation. Shubnikov–de Haas oscillations are observed from proximity detector oscillator measurements up to 60 T. We experimentally extract several frequencies, and through comparison to first-principles calculations, identify corresponding electronic bands. For H // c , two strong oscillations, F 1 ≈ 109 and F 2 ≈ 302 T, allow us to determine effective masses 0.266 m 0 and 0.300 m 0 ( m 0 is the free-electron mass), respectively. The topology of these bands is discussed.