Structure and magnetic properties of RE2CuIn3 (RE = Ce, Pr, Nd, Sm and Gd)

摘要

The ternary copper indides RE2CuIn3 RECu0.5In1.5 (RE = Ce, Pr, Nd, Sm and Gd) were synthesized from the elements in sealed tantalum tubes in an induction furnace. They crystallize with the Caln(2)-type structure, space group P6(3)/mmc, with a statistical Occupancy of copper and indium on the tetrahedral substructure. These indides show homogeneity ranges RECuxIn2-x. Single crystal structure refinements were performed for five crystals: CeCu0.66In1.34 (a = 479.90(7) pm, c = 768.12(15) pm), PrCu0.52In1.48 (a = 480.23(7) pm, c = 759.23(15) pm), NdCu0.53In1.47 (a = 477.51(7) pm, c = 756.37(15) pm), SmCu0.46In1.54 (a = 475.31(7) pm, c = 744.77(15) pm), and GdCu0.33In1.67 (a = 474.19(7), c = 737.67(15) pm). Temperature-dependent susceptibility measurements show antiferromagnetic ordering at T-N = 4.7 K for Pr2CuIn3 and Nd2CuIn3 and 15 K for Sm2CuIn3. Fitting of the Susceptibility data of the samarium compound revealed an energy gap Delta E = 39.7(7) K between the ground and the first excited levels. (C) 2008 Elsevier Inc. All rights reserved.