Neutron scattering and muon spin rotation (μSR) measurements on single-crystal SmAu₃Al₇ reveal magnetically ordered states associated with successive transitions at T ₍ = 2. 8 K and T^* = 0. 9 K. Magnetic Bragg peaks appear below T ₍ with an incommensurate (IC) propagation vector q = (0. 30, 0, 1. 33). μSR detects spontaneous internal fields below T ₍, and the spectral shape is consistent with the IC magnetic ordering. No anomalies are observed at T^*, indicating that the magnetic structure remains essentially unchanged below and above T^*. The magnetic order is revealed to be a spatially homogeneous long-range ordered state, rather than a partially disordered state proposed in earlier studies. The possible connection between the IC magnetic order and the enhanced low-temperature magnetic specific heat is discussed.
Higashinaka et al. (Fri,) studied this question.