Ferromagnetic spin fluctuations in the filled skutterudite SrFe4As12 revealed by 75As NMR-NQR measurements

Ding, Qingping; Rana, Khusboo; Nishine, K.; Kawamura, Y.; Hayashi, J.; Sekine, C.; Furukawa, Yuji

Ferromagnetic spin fluctuations in the filled skutterudite SrFe4As12 revealed by 75As NMR-NQR measurements

File

IS_J_9795.pdf (701.5 KB)

Date

2018-10-31

Authors

Ding, Qingping

Rana, Khusboo

Nishine, K.

Kawamura, Y.

Hayashi, J.

Sekine, C.

Furukawa, Yuji

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Organizational Unit

Ames National Laboratory

Ames National Laboratory is a government-owned, contractor-operated national laboratory of the U.S. Department of Energy (DOE), operated by and located on the campus of Iowa State University in Ames, Iowa.

For more than 70 years, the Ames National Laboratory has successfully partnered with Iowa State University, and is unique among the 17 DOE laboratories in that it is physically located on the campus of a major research university. Many of the scientists and administrators at the Laboratory also hold faculty positions at the University and the Laboratory has access to both undergraduate and graduate student talent.

Organizational Unit

Physics and Astronomy

Physics and astronomy are basic natural sciences which attempt to describe and provide an understanding of both our world and our universe. Physics serves as the underpinning of many different disciplines including the other natural sciences and technological areas.

Department

Ames National LaboratoryPhysics and Astronomy

Abstract

75As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements have been carried out to investigate the magnetic and electronic properties of the filled skutterudite metallic compound SrFe4As12. The temperature dependence of Knight shift K determined by the NQR spectrum under a small magnetic field (≤0.5T) shows the similar temperature dependence of the magnetic susceptibility χ which exhibits a broad maximum at T∗∼50 K. The nuclear spin-lattice relaxation rate divided by temperature 1/T1T increases with decreasing temperature and exhibits a broad maximum at T∼70 K, similar to the case of χ. The temperature dependence of K and 1/T1T is reasonably explained by a simple model where we assume a concave-shaped band structure near the Fermi energy. Based on a Korringa ratio analysis using the T1 and K data, ferromagnetic spin fluctuations are found to exist in SrFe4As12. These results indicate that SrFe4As12 can be characterized to be a metal with ferromagnetic correlations and also the peculiar band structure responsible for the suppression of 1/T1T and K at low temperatures.