Abstract

The crystal structures of three new intermetallic ternary compounds in the LnNiSb 3 family have been characterized by single crystal X-ray diffraction. PrNiSb 3, NdNiSb 3 and SmNiSb 3 all crystallize in an orthorhombic space group, Pbcm, Z=12, with a=12.5700Å, b=6.2010Å, c=18.670Å, and V=1431.64Å3; a=12.5090Å, b=6.1940Å, c=18.3350Å, and V=1420.61Å3; and a=12.3900Å, b=6.1760Å, c=18.2650Å, and V=1397.65Å3, for Ln=Pr, Nd and Sm, respectively. These compounds consist of rare-earth atoms located above and below layers of nearly square, buckled Sb nets, along with layers of highly distorted edge- and face-sharing NiSb 6 octahedra. Resistivity data indicate metallic behavior for all three compounds. Magnetization measurements show antiferromagnetic behavior with TN=4.5K, 4.6 K, and 2.9 K. Effective moments of 3.62 μ B, 3.90 μ B and 0.80 μ B are found for PrNiSb 3, NdNiSb 3 and SmNiSb 3, respectively, and are consistent with Pr 3+, Nd 3+, and Sm 3+. Structure of PrNiSb 3 viewed down the b-axis containing Pr atoms located between layers of nearly square Sb nets and highly distorted Ni-centered octahedra. © 2004 Elsevier Inc. All rights reserved.