Linear magnetoresistance and structural distortion in layered SrCu4-x P2 single crystals

Here we report a systematic study on layered metal SrCu4-x P2 single crystals combined with transport, magnetization, thermodynamic measurements and structural characterization. We found the crystals show large linear magnetoresistance without any sign of saturation with magnetic field up to the 30 T. We also observed a phase transition with significant anomaly in resistivity and heat capacity at Tp ~ 140 K. Thermal expansion measurement reveals a subtle lattice parameters variation near Tp , i.e. ΔLc /Lc ~ 0.062%. The structural characterization proves that there is no structure transition below and above Tp . All these results suggest that the nonmagnetic transition SrCu4-x P2 should be associated with structural distortion.