Large magnetoresistance and thermoelectric properties of a quasi-skutterudite Ca3Pt4Sn13 single crystal

Abstract

We conducted a detailed study of the quasi-skutterudite Ca₃Pt₄Sn₁₃ single crystal through measurements of electrical resistivity, Hall effect, specific heat, and thermoelectric properties. The resistivity exhibited metallic behavior from 300 to 2 K. The results of resistivity, the Wilson ratio, and low-temperature magnetic susceptibility indicated non-Fermi liquid behavior in the Ca₃Pt₄Sn₁₃ crystal. Ca₃Pt₄Sn₁₃ crystals showed a large longitudinal magnetoresistance (MR) of up to 200% at 5 T and 2 K for a magnetic field applied along the [110] direction. Combined with first-principles calculation results, we believe that carrier mobility is an important factor contributing to the large MR phenomenon. Meanwhile, we also performed angle-resolved MR (AMR) measurements on the Ca₃Pt₄Sn₁₃ crystal. An eight-fold symmetry in the AMR was observed in the low-temperature region, indicating that Ca₃Pt₄Sn₁₃ could be a potential candidate for valleytronics. Furthermore, the negative slope and linear dependence observed in the Hall resistance indicated electron conductivity, while the thermoelectric power results suggested the presence of hole-like carriers. The different signs of the Hall and Seebeck coefficients could be related to the unique structure of the Fermi surface boundaries in the Ca₃Pt₄Sn₁₃ crystal. In conjunction with the above experimental observations, we found that the carrier mobility, carrier concentration, Hall coefficient, Seebeck coefficient, thermal conductivity, magnetic susceptibility, MR, and AMR all showed significant changes when the temperature dropped below T^*, indicating that they might share a common origin closely related to the T^* phase. The current findings could provide a non-superconducting system to investigate the intrinsic origin of T^* in the Ca₃T₄X₁₃ family.