Coexistence of antiferromagnetic and ferromagnetic spin correlations in $\mathbf{Ca}{\left({\mathbf{Fe}}_{1-x}{\mathbf{Co}}_x\right)}_2{\mathbf{As}}_2$ revealed by ${}^{75}\mathbf{As}$ nuclear magnetic resonance

Journal Article · Tue Nov 22 00:00:00 EST 2016 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.94.174512· OSTI ID:1342923

Cui, J.; Wiecki, P.; Ran, S.; Bud'ko, S. L.; Canfield, P. C.; Furukawa, Y.

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 reanalyzed 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.

• Research Organization: Ames Lab., Ames, IA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: AC02-07CH11358
• OSTI ID: 1342923
• Report Number(s): IS-J 9160; PRBMDO
• Journal Information: Physical Review B, Vol. 94, Issue 17; ISSN 2469-9950
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY