Spin wave stiffness and damping in a frustrated chiral helimagnet Co${}_8$Zn${}_8$Mn${}_4$ as measured by small-angle neutron scattering

Abstract

Multiple intriguing low temperature phenomena have recently been discovered in the family of chiral cubic Co-Zn-Mn compounds with $\beta -$Mn-type structure. In particular, Co${}_8$Zn${}_8$Mn${}_4$ displays a reduction of the helical spiral pitch on cooling, along with lattice shape transformations of metastable skyrmions and the manifestation of peculiar magnetic textures due to strong magnetocrystalline anisotropy. Here we report on temperature-dependent measurements of helimagnon excitations in the field polarized regime Co${}_8$Zn${}_8$Mn${}_4$ using the spin wave small-angle neutron scattering (SWSANS) technique. By applying a new analytical expression to interpret the data, quantitative estimates for both spin wave stiffness and damping are extracted across a wide temperature range between 70 K and 250 K. We speculate that their non-trivial temperature-dependencies arise due to the effects of magnetic frustration arising from Mn magnetic moments, which is further reflected in continuous variations of both exchange and Dzyaloshinskii-Moriya interactions.

10 pages, 4 figures. Accepted to Physical Review Research

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Cited by in corpus (6)

• Skyrmion Alignment and Pinning Effects in a Disordered Multi-Phase Skyrmion Material Co8Zn8Mn4
• Anomalous electrical transport and magnetic skyrmions in Mn-tuned Co9Zn9Mn2 single crystals
• Observation by SANS and PNR of pure Néel-type domain wall profiles and skyrmion suppression below room temperature in magnetic [Pt/CoFeB/Ru]${}_{10}$ multilayers
• Observation of magnetic skyrmion lattice in Cr${}_{0.82}$Mn${}_{0.18}$Ge by small-angle neutron scattering
• Small-angle neutron scattering in fully polarized phase of non-collinear magnets with interfacial-like DMI
• Helical spin dynamics in Cu${}_2$OSeO${}_3$ as measured with small-angle neutron scattering