GD ESR IN UPT3

Gd-ESR experiments are reported on UPt3. As a function of temperature, the linewidth at resonance absorption which is a measure of the longi tudinal relaxation rate, reveals the typical heavy-fermion behavior wi th an increase of the Korringa slope with decreasing temperatures. The enhanced Korringa slope is due to the formation of heavy quasiparticl es. No anomaly due to the onset of long-range magnetic order could be defected. The ESR results compare reasonably well with published NMR d ata (C) 1997 Published by Elsevier Science Ltd.