Investigation of the effect of Ni substitution on the physical properties of Ce(Cu(1-x)Ni(x))(y)Sb(2).

Single crystals of Ce(Cu(1-x)Ni(x))(y)Sb(2) (x = 0, 0.25, 0.37, 0.46; y∼0.7) were synthesized using a flux growth method and crystallize in the tetragonal P4/nmm space group with lattice parameters of a∼4.4 Å and c∼9.8 Å. The effects of Ni substitution on the magnetic and electrical transport properties are investigated. Three of the analogues (with x = 0, 0.37, and 0.46) show antiferromagnetic behavior while the x = 0.25 sample is paramagnetic down to 2 K. Field-dependent magnetization data as well as resistivities are presented. Positive magnetoresistance behaviors above 70% are observed for the analogues with x = 0, 0.37, and 0.46 at 3 K and up to 9 T. The La analogue La(Cu(0.2)Ni(0.8))(y)Sb(2), has been synthesized and large, positive magnetoresistance of ∼300% is observed at 3 K and 9 T.

Discovery of beta-LnNiSb3 (Ln = La, Ce): crystal growth, structure, and magnetic and transport behavior.

A new polymorph of CeNiSb3 has been grown from a Sn flux and characterized by single-crystal X-ray diffraction. beta-CeNiSb3 crystallizes in the orthorhombic space group Pbcm (No. 57) with Z = 8. The unit cell parameters are a = 12.9170(2) A, b = 6.1210(5) A, c = 12.0930(6) A, and V = 956.13(9) A3. Its layered structure contains structural motifs similar to that of the first form of CeNiSb3 and consists of Ce atoms inserted between anionic layers of nearly square infinity2[Sb] nets and distorted infinity2[NiSb2] octahedra. We report the synthesis, magnetization, electrical resistivity, and specific heat of the new form of CeNiSb3 and compare the structures and physical properties of both polymorphs.