Magnetic susceptibility of (La,Ce) Al2 alloys

The low-field magnetic susceptibility of (La, Ce)Al₂ alloys with 1–20 at-% Ce was measured between 0.04 and 4 K. Up to 1.5 at-% Ce the impurity contribution to the susceptibility exhibits features which can be described in terms of a combined influence of the crystalline electric field and the Kondo effect. At very low temperatures the onset of interactions between the Ce impurities is indicated. The impurity coupling interactions determine the dependence on temperature and concentration of the more concentrated alloys. For the dilute alloys the impurity magnetization was determined from measurements of the susceptibility in magnetic fields up to 10 kOe. The magnetization as a function of temperature and field shows a typical anomaly which has been observed also in other Kondo systems.