Ce2Ni2Cd - A new intermediate-valent cerium compound

Ce2Ni2Cd was synthesized by reacting the elements in a sealed tantalum tube using a high-frequency furnace with a water-cooled sample chamber, The str ucture was refined from single-crystal X-ray data: ordered U3Si2 type, P4/m bm, a = 755.67(8) pm, c = 375.14(6) pm, wR2 = 0.0408, 232 F-2 values, and 1 3 parameters. A refinement of the occupancy parameters showed defects on th e nickel site, resulting in a composition of Ce2Ni1.88(1)Cd for the crystal investigated, The structure may be described as an intergrowth of CsCl and AlB2 related slabs of compositions CeCd and CeNi2. Magnetic susceptibility measurements indicate intermediate-valent behavior of the cerium atoms. Th e susceptibility data can be fit to a modified Curie-Weiss expression with Theta(p)=-5.2(2)K, mu(exp) = 0.79(3) mu(B)/Ce, and a temperature-independen t contribution chi(0) = 67.5(7) x 10(-9) m(3)/ mel. Temperature-dependent r esistivity measurements indicate metallic behavior with a specific resistiv ity of 140 +/- 20 mu Omega cm at room temperature, Below 50 K the specific resistivity reveals a T-2 dependence with rho(0) = 84.4(1) mu Omega cm and A = 0.0056(1) (mu Omega cm)/K-2, (C) 2000 Academic Press.