Local structure determination in helimagnetic ${\mathrm{Co}}_{8}{\mathrm{Zn}}_{8}{\mathrm{Mn}}_{4-x}{\mathrm{Fe}}_{x}$

Abstract

We have carried out a structural and magnetic characterization of Co 8 Zn 8+y Mn 4−y−x Fe x by means of bulk techniques, powder neutron scattering and Mössbauer spectroscopy. From our data, we derive the main magnetic parameters and carry out a detailed structural characterization. We observe that disorder is present in our samples in various forms and that this seems to be generic for this class of materials. However, the disorder appears to have little impact on the character of the magnetic phases, and thus seems to be of no relevance for the skyrmionic phases established for these types of materials.

Muon spin rotation and relaxation study on Nb$_{1-y}$Fe$_{2+y}$

“…In particular, the "ordinary" exponential muon relaxation in Nb 1−y Fe 2+y seems also to suggest that structural disorder is not an issue to the same degree as for UCu 4 Pd, CePd 1−x Rh x or even CeFePO (where a spin glass transition has been detected in single crystalline material) 9,37,39 , and that we are dealing with a comparatively clean magnetic system. Conceptually, this observation might simply reflect that in itinerant magnetic systems -because of the spatially extended electronic states carrying magnetism -crystallographic disorder is less an issue than in local moment systems, as for instance demonstrated by the insensitivity of skyrmionic behavior to crystallographic disorder in Co 8 Zn 8 Mn 4−x Fe x 45 .…”

Muon spin rotation and relaxation study on Nb1−yFe2+y

“…In particular, the exponential muon relaxation in Nb 1−y Fe 2+y suggests that structural disorder is not an issue to the same degree as for UCu 4 Pd, CePd 1−x Rh x or even CeFePO (where a spin glass transition has been detected in single-crystalline material) [9,37,39], and that we deal with a comparatively clean magnetic system. Conceptually, this observation might simply reflect that in itinerant magnets-because of the spatially extended electronic states-crystallographic disorder is less an issue than in local moment systems, as for instance demonstrated by the insensitivity of skyrmionic behavior to crystallographic disorder in Co 8 Zn 8 Mn 4−x Fe x [45].…”