Anisotropy of Magnetic and Transport Properties οf $UAuSb_2$ Single Crystals

The uranium-gold diantimonide $UAuSb_2$ belongs to a numerous family of ternary compounds crystallizing in a tetragonal structure of the $HfCuSi_2$-type (space group P4/nmm). In this paper the results of magnetization, electrical resistivity and thermopower measured along the main crystallographic directions are reported. Two magnetic transitions, a ferromagnetic one at $T_C$ =31 K and probably an antiferromagnetic one at $T_N$ = 43 K were found. The spontaneous magnetization at 1.9 K amounts about 0.8 $μ_B$ for B ∥ c-axis. Electrical resistivity for j ⊥ c-axis exhibits a $T^2$ exp(-Δ/kT) dependence at low temperatures and a Kondo effect at higher temperatures above $T_N$. The thermopower S for both main crystallographic directions shows a maximum at the temperature close to $T_C$ and the lack of any anomaly at $T_N$.