Dramatic evolution of magnetic properties induced by electronic change in Ce(Pd_1-xAg_x)₂Al₃

By measuring the lattice parameters (a, c), the magnetic susceptibility χ(T) and magnetization M(H), the specific heat C(T), and the electrical resistivity ρ(T) for Ce(Pd_1-xAg_x)₂Al ₃, we found that with increasing x the system undergoes a variation from antiferromagnetism to ferromagnetism at x∼0.05 then back to antiferromagnetism at x∼0.45. The magnetic evolution, together with the Kondo temperature T_K that is inferred to decline with x, closely resembles that of Ce(Pd_1-xCu_x)₂Al₃. The two systems have the same electronic but opposite volume change; resemblance between them indicates the dominant effect in the substitution is caused by electronic change but not volume change. Modification of the RKKY interaction may not account for the unusual magnetic evolution.