Evolution of helimagnetic correlations in Mn1-xFexSi with doping

Abstract

We present a comprehensive small-angle neutron scattering study of the doping dependence of the helimagnetic correlations in Mn1−xFexSi. The long-range helimagnetic order in Mn1−xFexSi is suppressed with increasing Fe content and disappears for x>x∗≈0.11, i.e., well before xC≈0.17 where the transition temperature vanishes. For x>x∗, only finite isotropic helimagnetic correlations persist which bear similarities with the magnetic correlations found in the precursor phase of MnSi. Magnetic fields gradually suppress and partly align these short-ranged helimagnetic correlations along their direction through a complex magnetization process