Magnetic field effects on transport properties of PtSn4

The anisotropic physical properties of single crystals of orthorhombic PtSn 4 are reported for magnetic fields up to 140 kOe, applied parallel and perpendicular to the crystallographic b axis. The magnetic susceptibility has an approximately temperature-independent behavior and reveals an anisotropy between the ac plane and b axis. Clear de Haas-van Alphen oscillations in fields as low as 5 kOe and at temperatures as high as 30 K were detected in magnetization isotherms. The thermoelectric power and resistivity of PtSn 4 show the strong temperature and magnetic field dependencies. A change of the thermoelectric power at H = 140 kOe is observed as high as 50 μV/K. Single crystals of PtSn 4 exhibit very large transverse magnetoresistance of 5 × 10 5 % for the ac plane and of 1.4 × 10 5 % for the b axis resistivity at 1.8 K and 140 kOe, as well as pronounced Shubnikov de Haas oscillations. The magnetoresistance of PtSn 4 appears to obey Kohler's rule in the temperature and field range measured. The Hall resistivity shows a linear temperature dependence at high temperatures followed by a sign reversal around 25 K which is consistent with thermoelectric power measurements. The observed quantum oscillations and band structure calculations indicate that PtSn 4 has three-dimensional Fermi surfaces.