Substitution effects of p-block elements on magnetic properties of GdNi4B, GdNi4In, GdCo4Al and DyCo4.6Si0.4

The polycrystalline CeCo ₄B-type GdNi ₄B (space group P6/ mmm, N 191, hP12), CaCu ₅-type GdCo ₄Al and DyCo _4.6Si _0.4 (space group P6/ mmm, N 191, hP6) and MgCu ₄Sn-type GdNi ₄In (space group F-43 m, N 216, cF24) were prepared by arc melting with following annealing. The magnetic ordering and magnetocaloric effects of these compounds have been investigated using magnetic measurements in fields up to 90 kOe. GdNi ₄B and GdNi ₄In show dominant ferromagnetic ordering of Gd sublattice with T _C of 39 K and 24 K, respectively with magnetic entropy change of −11.3 J/kg·K for GdNi ₄B and −11.8 J/kg·K for GdNi ₄In for a field change of 50 kOe. GdCo ₄Al and DyCo _4.6Si _0.4 exhibit high-temperature dominant ferromagnetic ordering of Co sublattice with low-temperature spin-reorientation transformation of magnetic ordering and dominant ordering of rare earth sublattice in width temperature interval. In a field change of 50 kOe, the compensation temperature of DyCo _4.6Si _0.4 is followed via table-like magnetic entropy change of −1.0 J/kg·K at ∼40–240 K, while GdCo ₄Al exhibits magnetic entropy change of around −0.6 J/kg·K at ∼150–300 K.