mu SR studies of magnetic correlations in Pt and Cu doped CeNiSn

The development of magnetic correlations at low temperatures was studied by muon spin relaxation (mu SR) and specific heat measurements in CePtxNi1-xSn (x = 0.12, 0.2) and CeCuxNi1-xSn (x = 0.05, 0.1, 0.2). Doping with Pt up to 20% increases the magnetic correlations only weakly. In contrast, doping with either 10% or 20% Cu strengthens the correlations up to the point of forming a spin-glass-like state and finally long range order. The large difference in magnetic behavior between CePtxNi1-xSn and CeCuxNi1-xSn shows that the increase in d electron density when doping with Cu is likely to be the important factor for strengthening magnetism.