Magnetic properties, crystal and electronic structure of GdNi5−xCux series

The effect of Ni/Cu substitution on the magnetic properties, crystal and electronic structure of the polycrystalline GdNi5−xCux series has been studied. All compounds crystallize in the hexagonal CaCu5 type of crystal structure (space group P6/mmm). The temperature dependence of magnetic phase transition (Tmag) estimated from χAC(T) susceptibility as well as magnetization M(T) below room temperature indicates the maximum for x = 1.0 copper concentration. In the paramagnetic range (above 300 K) the magnetic susceptibilities follow a Curie–Weiss-type dependence. The effective magnetic moments are higher than theoretical value for free Gd3+.From X-ray photoelectron spectroscopy (XPS) data the valence band as well as the core level spectra have been analyzed. The filling of Ni3d band in the GdNi5−xCux system by charge transfer of Gd conduction electrons is revealed by a reduction of the satellite intensities in the Ni2p core level spectrum. The obtained results exhibit that the valence bands at the Fermi level are dominated by hybridized Ni3d and Gd5d states, when Cu3d states are rather localized about 3 eV below the Fermi level. Quite good relation between the magnetic properties and electronic structure has been found.

Research highlights▶ In the manuscript we present original measurements of the crystal and electronic structure and the magnetic properties of polycrystalline GdNi5−xCuz intermetallic compounds. ▶ First of all the electronic structure studied by XPS method is the new and novel in the presented paper. ▶ The magnetic properties of studied system is closely related to the electronic structure.