Tuning the magnetic anisotropy in CeRhIn5 via Gd substitution

Abstract

In strongly correlated materials, the presence of defects may fundamentally affect both macro and microscopic properties of the system. Here we investigate the effect of Gd substitution in the Kondo antiferromagnet CeRhIn5. At a concentration of only 11% Gd, the magnetic anisotropy of CeRhIn5 is drastically reduced at high temperatures whereas its antiferromagnetic transition, T Ce N = 3.8 K, is linearly suppressed with Gd at low temperatures. The extrapolation of T Ce N to zero temperature occurs at a critical concentration of xc ∼ 0.63, which is above the 2D percolation limit found in Ce1−xLaxRhIn5 (xc ∼ 0.4), but very close to the 3D percolation limit found in Gd1−xLaxRhIn5 and Ce1−xLaxIn3 (xc ∼ 0.65), in agreement with the more isotropic magnetic response.