Development of magnetic order in CeCu2(Si1-xGex)(2)

Measurements of specific heat (C(p)), AC and DC susceptibility, and resistivity were carried out on samples of CeCu(2)(Si(1-x)Ge(x))(2). The system evolves continuously from the heavy fermion state at x = 0 to an antiferromagnetically (AF) ordered state at x = 1, although the magnetic structure undergoes significant modifications. The results strongly suggest that the AF-ordering emerges from the A-phase of CeCu(2)Si(2). Below the ordering temperature a systematic change in curvature in C(p)(T) is observed for x greater than or equal to 0.6, that gets more pronounced with decreasing x, and al x = 0.4 a sharp anomaly is observed suggesting the existence of a critical point for 0.3 < x < 0.5. Below 1 K, a small anomaly is present al some concentrations. The results are compared with those on the Ce(Cu(1-x)Ni(x))(2)Ge(2) system.