Crystal structure and magnetic properties in CeCu1−xAlxGe (0.1≦x≦0.5)

As judged by x-ray-powder patterns and crystallographic data, a 10–50% substitution of Al on the Cu site of CeCuGe prefers to crystallize in a hexagonal ZrBeSi-type structure with space group P63/mmc rather than AlB2-type structure with space group P6/mmm. The substitution of Cu by Al in CeCu1−xAlxGe was found to be able to attenuate the localized Ce-4f moments. As determined from the electrical-resistivity and magnetic susceptibility measurements, both the ferromagnetic transition temperature Tc value and the magnitude of the spontaneous magnetization in the series CeCu1−xAlxGe reflect the decreasing strength of exchange interactions with the Al concentration. In addition, the resistivity data in CeCu1−xAlxGe revealed the simultaneous contributions of exchange interactions, Kondo effects, crystal field effects and phonons.