Electron paramagnetic resonance of (Lasub(1-y-x)Gdsub(y)Cesub(x))Al2

In the EPR of (Lasub(1-y-x)Gdsub(y)Cesub(x))Al2 a bottleneck in the relaxation of the conduction electrons to the lattice is present at sufficiently high Gd-concentrations. The bottleneck can be broken by decreasing the Gd-concentration or by adding cerium as a spin-flip-scatterer. G-factor and line broadening are measured for (Lasub(1-y)Gdsub(y))Al2 and (Lasub(1-y-x)Gdsub(y)Cesub(x))Al2 as a function of temperature and Gd- and Ce-concentrations. The cerium induced relaxationsrate deltasub(eL)(Ce) increases linearly with Ce-concentration up to x approximately 0.025. This corresponds to the fact, well known by measurements of the Kondo anomalies, that cerium impurities show no significant interaction up to rather high concentrations. (orig.)