Synthesis, structure, and magneto-transport of LnNi1-xSb2 (Ln = Y, Gd-Er)

Single crystals of the ternary antimonides LnNi(1-x)Sb(2) (Ln = Y, Gd-Er; x similar to 0.4) have been grown from antimony flux. X-ray diffraction experiments reveal that these compounds crystallize in the tetragonal space group P4/nmm (No. 129) with Z = 2. Lattice parameters are a similar to 4.3 angstrom and c similar to 9.3 angstrom. Adopting the HfCuSi(2) structure type, these compounds are layered and consist of Ln-capped Sb square nets and NiSb(4) tetrahedra arranged in an anti-PbO fashion. The LnNi(1-x)Sb(2) compounds show antiferromagnetic ordering and field-dependent magnetization data are also presented. Transport measurements indicate metallic behavior and, most interestingly, positive magnetoresistance for each compound, with large positive magnetoresistance [MR(%) = (rho(H) - rho(0))/rho(0) x 100] above 100% for the Y-, Dy-, and Ho-analogues at 3 K and 9 T.