Influence of Ho substitution on the structural and magnetic properties of DyCu₅Sn

Chem. Met. Alloys 12 (2019) 44-49

https://doi.org/10.30970/cma12.0394

A. ZELINSKIY, M. BOBNAR, O. SICHEVYCH, L. AKSELRUD, L. ROMAKA, R. GLADYSHEVSKII

Several samples from the homogeneity range of the solid solution Dy_1‑xHo_xCu₅Sn (x = 0-0.1) were prepared by arc melting of the elements and annealed first at 1100 K and then at 870 K. The crystal structure of DyCu₅Sn was solved from single-crystal X-ray diffraction data, and Rietveld refinements of X-ray powder diffraction data were carried out to analyze the evolution of the lattice parameters in the solid solution. The Dy_1‑xHo_xCu₅Sn phase crystallizes with the structure type CeCu₅Au (an ordered variant of the CeCu₆ type). The replacement of Dy by Ho is accompanied by a decrease of the volume of the unit cell. The magnetic behavior of the Dy_1‑xHo_xCu₅Sn intermetallics was studied by magnetic susceptibility (χ) measurements in the temperature range 1.8-400 K. Contrary to earlier reports a paramagnetic Curie temperature of -3.9 K was found for DyCu₅Sn, but the magnetic behavior of the sample Dy_0.9Ho_0.1Cu₅Sn, with a critical temperature near 0 K, can be described by a quantum phase transition associated with an antiferromagnetic transformation.

Projection of the structure of DyCu₅Sn onto the XZ plane and coordination polyhedra of the different atoms.

Keywords

Intermetallics / Crystal structure / X-ray diffraction / Magnetic properties / Quantum phase transition