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Electronic States of Boron in Superconducting MgB$_2$ Studied by $^{11}$B NMR

A. Gerashenko·K. Mikhalev·S. Verkhovskii·T. D'yachkova·A. Tyutyunnik·V. Zubkov
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Abstract

NMR spectra and nuclear spin-lattice relaxation rate $T_1^{-1}$ of $^{11}$B have been measured in superconducting polycrystalline MgB$_{2}$ with $T_C^{ons}\cong 39.5K$. It is shown that $(T_{1}T)^{-1}$ and the Knight shift $K_{s}$ are independent of temperature and nearly isotropic above $T_C$. Both of these quantities are decreased gradually in going to superconducting state. According NMR data the density of states (DOS) near the Fermi level is flat at the scale $\approx$ 500K. Some conclusions on the orbital content of the DOS at the Fermi level was done and compared with the results of the band structure calculations.

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A. Gerashenko, K. Mikhalev, S. Verkhovskii, T. D'yachkova, A. Tyutyunnik, V. Zubkov. 2001-02-23. Electronic States of Boron in Superconducting MgB$_2$ Studied by $^{11}$B NMR. https://arxiv.org/abs/cond-mat/0102421

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