[en] We investigate the pseudobinar metal alloys [Gd₀,22(La₁-x Yx)₀,78] [Zn₁-xCd_x], 0≤ x ≥ 1, which are solid solution with a C; Cl structure where the basic parameters determining magnetic properties, are constant; the concentration of magnetic ions, the concentration of conduction electrons, and the lattice constant. However, a strong difference in the magnetic properties and continuous transition from the ferromagnetic phase at 0,4< x ≥ 0,8 to the reentrant spin-glass at x-> 0 and x -> 1 were revealed depending on the parameter of non magnetic ions substitution x. A long-range ferromagnetic order was observed only at the maximal compositional disorder of non-magnetic ions. It is shown that these ''magnetic anomalies'' are conditioned by the alloy effects, i.e., by the dependence of the mean free path of electrons and effective mass of electrons on x. Taking into account the alloy effects, the RKKY interaction is calculated as a function of x, and in the mean-field theory approximation the values of the paramagnetic Curie-Weiss temperature were obtained which are in good agreement with experimental data