Coexistence of antiferromagnetic and ferromagnetic spin correlations in Ca(Fe1-xCox)2As2 revealed by 75As nuclear magnetic resonance

Abstract

Recent nuclear magnetic resonance (NMR) measurements revealed the coexistence of stripe-type antiferromagnetic (AFM) and ferromagnetic (FM) spin correlations in both the hole- and electron-doped BaFe${}_2$As${}_2$ families of iron-pnictide superconductors by a Korringa ratio analysis. Motivated by the NMR work, we investigate the possible existence of FM fluctuations in another iron pnictide superconducting family, Ca(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$. We re-analyzed our previously reported data in terms of the Korringa ratio and found clear evidence for the coexistence of stripe-type AFM and FM spin correlations in the electron-doped CaFe${}_2$As${}_2$ system. These NMR data indicate that FM fluctuations exist in general in iron-pnictide superconducting families and thus must be included to capture the phenomenology of the iron pnictides.

8 pages, 5 figures, submitted to Phys. Rev. B

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Cited by in corpus (3)

• Magnetic fluctuations and superconducting properties of CaKFe4As4 studied by 75As NMR
• Effect of proton irradiation on the normal state low-energy excitations of Ba(Fe${}_{1-x}$Rh${}_x$)${}_2$As${}_2$ superconductors
• Toward the Mott state with Magnetic Cluster Formation in Heavily Cu-Doped NaFe${}_{1-x}$Cu${}_x$As