mu SR magnetic response of CeCuSn

mu SR studies in zero, longitudinal and transverse fields were carried out in the temperature range between 2 and 150 K on a polycrystalline powder sa mple. The data confirm the presence of two magnetic states, but each contai ns differently correlated spins. A first magnetic transition commences near 11 K and extends down to 7.5 K. In this temperature range a gradual format ion of short-range correlated spins is seen which coexist with spins keepin g their paramagnetic nature. The rate of formation is maximal around 8.5 K, which is probably the cause for a peak seen previously in specific heat da ta. A second transition seen in specific heat at 7.4 K signals, according t o the mu SR data, the long-range ordering of the remaining paramagnetic fra ction. The short-range ordered fraction begins to lose its spin dynamics an d ends in a spin frozen state around 3.5 K. Whether the two magnetic surrou ndings (short- and long-range ordered) sensed by the muons at T much less t han 7.5 K reflect a magnetically inhomogeneous material or whether a homoge neous spin structure with only partially long-range ordered spins exists ca nnot be decided at this stage and calls for magnetic diffraction data. (C) 2000 Published by Elsevier Science B.V. All rights reserved.