μSR study of spin-glass freezing in Y1−xUxPd3 and UPd4 Disappearance of the ordered moment in the ‘Kondo regime’

Muon spin relaxation (μSR) measurements have been performed on polycrystalline specimens of Y1−xUxPd3 with x=0.1, 0.2, 0.4 and on UPd4. Spin-glass-like magnetic order was observed in UPd4 at Tg≅13 K and in Y0.6U0.4P d3 at Tg≅12 K. The average static random internal field Hint at the muon site is found to decrease very rapidly with U concentration x, indicating that the ordered static U moment rapidly disappears with decreasing U concentration around x≅0.2. Our results are consistent with the conjecture that Kondo screening eliminates the magnetic moment around this concentration.