The influence of Sc substitution on some physical properties of Sc_xHo_1–xNi₂ solid solutions

Abstract

Results of X-ray diffraction analysis, magnetization measurements, magnetic susceptibility, electrical resistivity, and heat capacity performed on polycrystalline Sc x Ho 1-x Ni 2 (0 ≤ x ≤ 1) solid solutions are reported. It was found that they crystallize with the formation of the C15 type Laves-phase superstructure. At low temperatures (below 20 K), the Sc x Ho 1-x Ni 2 solid solutions with 0 ≤ x ≤ 0.6 are ferromagnets. At higher temperatures, all solid solutions are Curie -Weiss paramagnets. Temperature dependences of the electrical resistivity exhibit the typical behaviour of metals. The heat capacity measurements allowed us to determine the Debye temperature. The magnetocaloric effect was estimated from measurements performed in a low magnetic field of 0.42 T.

Magnetic, electrical, and thermodynamic properties of the LaxHo1−xNi2 solid solutions

“…However, some authors [3,4] have reported the possible existence of a residual magnetic moment at nickel atoms. Moreover our recent investigations confirmed this assumption, namely, we have found that magnetic moments in some poorly diluted solid solutions, such as Lu 0.2 Ho 0.8 Ni 2 [5] and Sc 0.2 Ho 0.8 Ni 2 [6], are higher than that due to only holmium atoms. This also suggests the existence of a residual magnetic moment at the nickel atoms.…”

“…This superstructure, corresponding to space group F43m and having a doubled lattice parameter, is characterized by ordered vacancies at the rare earth metal sites. Furthermore, our previous studies confirmed that A x Ho 1−x Ni 2 (A = Y [9], Lu [5], Sc [6]) solid solutions crystallize with the formation of the Laves-phase superstructure (F 43m e.g. ).…”

Magnetic properties and specific heat of Dy1−xLaxNi2 compounds

“…However, the existence of the residual magnetic moment on nickel resulting in an increase of the total magnetic moment has been reported [10,11]. Our recent study confirmed this assumption: the magnetic moments of poorly diluted Ho 0.9 La 0.1 Ni 2 , Ho 0.85 La 0.15 Ni 2 [12], Ho 0.8 Lu 0.2 Ni 2 [13] and Ho 0.8 Sc 0.2 Ni 2 [14] solid solutions have been found to be higher than those due to holmium atoms only. In the R-Ni alloys, the main sources of the magnetic moment are electrons located in the unfilled f-level of lanthanide atoms.…”

Role of lanthanum in modifying the magnetic state in RNi2 solid solutions with R = Tb, Dy, Ho

“…x ≤ 0.8 but in the case of Ho 1-x La x Ni 2 similar to the Ho 1-x Y x Ni 2 and Ho 1-x Sc x Ni 2 system [20,21] the ferromagnetic order disappears after substitution of lanthanum in place of more than 80 % of holmium.…”