Anisotropic transport properties and high-mobility of charge carriers of antiferromagnetic GdAgSb2.

We report detailed magnetic and magnetotransport properties of single-crystalline GdAgSb2 antiferromagnet. The electronic transport properties show metallic behavior along with large, anisotropic, and non-saturating magnetoresistance (MR) in transverse experimental configuration. At 2 K and 9 T, the value of MR reaches as high as 1.8×10%. The anisotropic MR along with additional features for applied magnetic field along some specific crystallographic directions reveal the quasi-two-dimensional nature of the Fermi surface of GdAgSb2. Hall resistivity confirms the presence of two types of charge carriers. The high carrier mobilities ( 1.2×10cm2 V-1s-1) and nearlycompensated electron and hole-density ( 10cm-3) could be responsible for the large transverse MR in GdAgSb2. We have also observed the de Haas-van Alphen oscillations in the magnetization measurements below 7 K. Furthermore, the robust planar Hall effect, which persists up to high temperatures, could indicate the nontrivial nature of the electronic band structure for GdAgSb2. .