Tuning of magnetic properties and Kondo effect by Cu concentration in Ce(Pd1-xCux)2Al3

The electrical resistivity, magnetic susceptibility and specific heat measurements were per-formed on Ce(Pd1-xCux)(2)Al-3 (x = 0.0-0.7) system to investigate the effects induced by Cu substitution in the heavy fermion compound CePd2Al3. A dramatic evolution of the magnetic properties was observed with the substitution of Pd by Cu: (1) a small amount of Cu (x < 0.1) in CePd2Al3 leads to a rapid decrease of the antiferromagnetic transition temperature T-N; (2) passing through a crossover region without a long-range magnetic order, a ferromagnetic-like state, which reveals an enhanced magnetic susceptibility and a distinct peak in the specific heat curve at low temperatures, occurs around x = 0.1-0.4; (3) by furthering the substitution through a second crossover region, however, the antiferromagnetic ordering is recovered close to x = 0.5-0.7. A decrease tendency of the Kondo temperature T-K with increasing x is derived from the analysis on the specific heat results. It is suggested that the change of the conduction-electron concentration rather than the chemical pressure dominates the evolution of the physical properties in this system.