Magnetic and electronic properties of Mn4Si7

We present a systematic study of the magnetization, Hall effect and specific heat on single crystals of Mn4Si7. Curie-Weiss law is observed above 43 K. At low-temperature moments order in an anisotropic helical state and are aligned above 1 T. We observe an anomalous Hall effect in both rho(H) vs. B and in R-H vs. T curves and a field dependence of the low T specific heat due to spin fluctuations. The magnetic moments (p(eff) and p(sat)) are the lowest reported for similar itinerant magnetic systems, this suggests that Mn4Si7 is a good candidate to observe critical quantum fluctuations expected for a marginal Fermi liquid.