1. NMR Evidence of Antiferromagnetic Spin Fluctuations in Nd0.85Sr0.15NiO2.
- Author
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Cui, Yi, Li, Cong, Li, Qing, Zhu, Xiyu, Hu, Ze, Yang, Yi-feng, Zhang, Jinshan, Yu, Rong, Wen, Hai-Hu, and Yu, Weiqiang
- Subjects
ELECTRON configuration ,SPIN-lattice relaxation ,LOW temperatures ,SUPERCONDUCTIVITY ,BULK solids ,THIN films ,ANTIFERROMAGNETISM - Abstract
Despite the recent discovery of superconductivity in Nd
1–x Srx NiO2 thin films, the absence of superconductivity and antiferromagnetism in their bulk materials remains a puzzle. Here we report the1 H NMR measurements on powdered Nd0.85 Sr0.15 NiO2 samples by taking advantage of the enriched proton concentration after hydrogen annealing. We find a large full width at half maximum of the spectrum, which keeps increasing with decreasing the temperature T and exhibits an upturn behavior at low temperatures. The spin-lattice relaxation rate is strongly enhanced when lowering the temperature, developing a broad peak at about 40 K, then decreases following a spin-wave-like behavior at lower temperatures. These results evidence a short-range glassy antiferromagnetic ordering of magnetic moments below 40 K and dominant antiferromagnetic fluctuations extending to much higher temperatures. Our findings reveal the strong electron correlations in bulk Nd0.85 Sr0.15 NiO2 , and shed light on the mechanism of superconductivity observed in films of nickelates. [ABSTRACT FROM AUTHOR]- Published
- 2021
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