Systematic study of anisotropic transport and magnetic properties of RAgSb 2 (R=Y, La–Nd, Sm, Gd–Tm)

Abstract

Anisotropic measurements of the magnetic and transport properties have been performed on high-quality single crystals of the RAgSb 2 series of compounds with R=Y, La–Nd, Sm, Gd–Tm. For most of these compounds, strong magnetic anisotropies, created by crystalline electric field (CEF) splitting of the Hund's rule ground state, confine the moments to the basal plane. Additional anisotropy within the basal plane is also observed in DyAgSb 2, leading to a series of metamagnetic transitions. All of the compounds order antiferromagnetically at low temperatures except for the nonmagnetic compounds LaAgSb 2 and YAgSb 2 and the ferromagnetic compound CeAgSb 2. For R=Y, La–Nd, and Sm clear de Haas–van Alphen oscillations in fields as low as 30 kOe and at temperatures as high as 25 K can be measured. Throughout the series, the low-temperature transverse magnetoresistance is large [Δ ρ( H)/ ρ(0)≈60 in SmAgSb 2 at 55 kOe] and deviates strongly from quadratic behavior with field the dependence of Δ ρ( H)/ ρ(0) ranging between H 0.8 and H 1.5.