On the magnetic behaviour of ACo 2 (A = Y, Lu, Zr, Sc and Hf) compounds

Abstract

The magnetic properties of ACo 2 (A = Y, Lu, Zr, Sc, Hf) compounds were investigated in the temperature range 2–1100 K and fields up to 70 kOe. In order to avoid a possible alteration of the magnetic susceptibilities, χ, caused by the presence of magnetic ordered impurities, the χ values were obtained from magnetization isotherms, by extrapolation to H -1→0. At high temperatures, the ACo 2 (A = Y, Lu, Sc and Hf) compounds show temperature dependences of magnetic susceptibilities of Curie-Weiss type. In ZrCo 2, a more complex thermal variation of magnetic susceptibility is evidenced. At T ⪅ 15 K, the χ values for YCo 2 and LuCo 2 vary according to the relation χ = χ 0(1 + aT 2). The experimental data are analysed in the spin fluctuations model.