Crystal structure, thermal expansion and magnetic properties of Nd2Cu0.8Ge3 compound

Abstract

A new ternary intermetallic compound, Nd 2Cu 0.8Ge 3, was synthesized and its crystal structure was determined by Rietveld refinement of X-ray powder diffraction data. The Nd 2Cu 0.8Ge 3 compound crystallizes in space group I4 1/amd (No. 141), with a tetragonal a-ThSi 2 structure type, and a=0.41783(2) nm, c=1.43689(9) nm, Z=2 and D calc=7.466 g/cm 3. Using the high temperature powder X-ray diffraction (HTXRD) technique, the lattice thermal expansion behavior of the compound was investigated in the temperature range of 298-648 K, and the result shows that its unit-cell parameters increased anisotropically when temperature increased. The magnetic susceptibility measured in the temperature range of 5-300 K indicated antiferromagnetic order of Nd 2Cu 0.8Ge 3 at low temperatures, and the magnetic susceptibility can be well described over the range of 50-300 K using Curie-Weiss law. The calculated effective magnetic moment (μ eff) is 3.53 μ B and dominated by the contribution of the Nd 3+ ions. © 2012 Elsevier Ltd. All rights reserved.