Abstract
In SmB\(_6\), the prototypical material of valence fluctuations and Kondo semiconductors, there remain several unsolved problems in the bulk properties at low temperatures. We have studied a single crystalline sample of SmB\({_6}\) by \(^{11}\)B-nuclear magnetic resonance (NMR) measurements with the precise control of the field direction in the \(\left( \bar{1} 1 0 \right) \) plane. The temperature dependence of the nuclear quadrupole frequency \(\nu _\textrm{Q}\) and the full width at half maximum (FWHM), estimated from obtained spectra indicates that there are two distinct low-temperature regions in SmB\(_6\): the first is the region down to approximately 10 K, where a decrease in the FWHM and an increase in \(\nu _\textrm{Q}\) with lowering temperature are understood in the framework of the evolution of the hybridization effects between 4f and conduction electrons accompanied with an intermediate valence state. Below 10 K, the second region, \(\nu _\textrm{Q}\) and the FWHM undergo a sharp change in their temperature dependence. Through both electrical and magnetic interactions, the present results suggest that the low-temperature state below 10 K is dominated by additional physical properties other than the hybridization and the valence fluctuations.
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This work was supported by JSPS KAKENHI (Grants Nos. 22J15100 (2022), 16K05457, 21K03450, and 21K03475).
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This work was financially supported by JSPS KAKENHI (Grants Nos. 22J15100 (2022), 16K05457, 21K03450, and 21K03475).
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T.N. conducted experiments and prepared figures 1-2, and T.N. and M.T. wrote the main manuscript text. F.I. provided a high-quality sample. T.F. and Y.N. contributed to deepening the interpretation of the experimental results. All authors reviewed the manuscript.
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Nishikawa, T., Fujii, T., Nakai, Y. et al. Angle-controlled \(\mathrm {^{11}}\)B-NMR studies of Kondo insulator SmB\(_{6}\). Hyperfine Interact 245, 17 (2024). https://doi.org/10.1007/s10751-024-01858-5
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DOI: https://doi.org/10.1007/s10751-024-01858-5