The collapse of the p-f mixing in CeSb with Ni incorporation

We have synthesized Ce SbNi_0.15 single crystal and measured its magnetic and transport properties. X-ray powder diffraction studies reveal that CeSbNi_0.15 crystallizes in the cubic structure, like the host CeSb, with Ni atoms occupying interstitial sites. The magnetic susceptibility reveals an antiferromagnetic ordering at T_N = 9.5 K. The magnetization isotherm at 1.5 K shows a metamagnetic transition at 6.4 T. The field dependence of the magnetization at 5 K exhibits almost the same behaviour up to a field of 5.5 T for B ∥ [100], B ∥ [110] and B ∥ [111]. The resistivity exhibits a sharp rise below T_N which we attribute to the formation of a superzone gap. The obvious effect of Ni incorporation in CeSb is the absence of complex and strong anisotropic magnetic properties. This indicates that the p-f mixing in CeSb is strongly reduced by the incorporation of Ni in the interstitial site. We have also determined the solubility limit of Ni in polycrystalline compounds CeSbNi_x to be x ≈ 0.4, and studied their magnetic and transport properties. These studies show that T_N for CeSbNi_x alloys varies non-linearly with the Ni content, x.