Mn-induced Fermi-surface reconstruction in the SmFeAsO parent compound

Meinero, M. and Bonfà, P. and Onuorah, I.J. and Sanna, S. and De Renzi, R. and Eremin, I. and Müller, M.A. and Orain, J.-C. and Martinelli, A. and Provino, A. and Manfrinetti, P. and Putti, M. and Shiroka, T. and Lamura, G.

Volume: 11 Pages:
DOI: 10.1038/s41598-021-93625-7
Published: 2021

The electronic ground state of iron-based materials is unusually sensitive to electronic correlations. Among others, its delicate balance is profoundly affected by the insertion of magnetic impurities in the FeAs layers. Here, we address the effects of Fe-to-Mn substitution in the non-superconducting Sm-1111 pnictide parent compound via a comparative study of SmFe1-xMnxAsO samples with x(Mn) = 0.05 and 0.10. Magnetization, Hall effect, and muon-spin spectroscopy data provide a coherent picture, indicating a weakening of the commensurate Fe spin-density-wave (SDW) order, as shown by the lowering of the SDW transition temperature TSDW with increasing Mn content, and the unexpected appearance of another magnetic order, occurring at T∗≈ 10 and 20 K for x= 0.05 and 0.10, respectively. We attribute the new magnetic transition at T∗, occurring well inside the SDW phase, to a reorganization of the Fermi surface due to Fe-to-Mn substitutions. These give rise to enhanced magnetic fluctuations along the incommensurate wavevector Q2= (π± δ, π± δ) , further increased by the RKKY interactions among Mn impurities. © 2021, The Author(s).

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