Effect of Sc on magnetic properties and heat capacity of R1-xScxNi2 (R = Gd, Tb, Dy, Ho) solid solutions: Comparative analysis

This paper presents a review and a comparison of the influence of Sc on some physical properties of R1-xScxNi2 (R = Gd, Tb, Dy, Ho) solid solutions. The X-ray diffraction studies performed at room temperature have allowed us to reveal that all R1-xScxNi2 solid solutions solidify with the formation of a Laves-phase superstructure corresponding to the F (4) over bar 3m space group. The magnetic properties are dominated by ferromagnetism of the rare earth atoms. While, upon substitution, non-magnetic Sc causes a dilution of magnetic moments on the rare earth site, resulting in a decrease of the ordering temperature. In the case of Gd1-xScxNi2, Tb1-xScxNi2 and Dy1-xScxNi2, the ferromagnetic order retains as the scandium content increases to x = 0.8, whereas, for Ho1-xScxNi2, the magnetic order manifests itself only for the solid solutions with x <= 0.6. The Debye temperature, phonon and conduction electron contributions as well as the magnetic contribution to the heat capacity have been determined from heat capacity measurements. The magnetocaloric effect for selected solid solutions was determined in magnetic fields up to 1 T. (C) 2012 Elsevier Ltd. All rights reserved.