E 43 Electronic States of Boron in Superconducting MgB 2Studied by "B NMR / A. P. Gerashenko, K. N. Mikhalev, S. V. Verkhovskii, T. V. D'yachkova, A. P. Tyutyunnik, V. G. Zubkov // Applied Magnetic Resonance. - 2001. - Vol. 21. - P. 157-163 : il. - Bibliogr. : p. 162-163 (12 ref.) . - ISSN 0937-9347 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): БОРИД МАГНИЯ -- СВЕРХПРОВОДИМОСТЬ -- ЯМР Аннотация: Nuclear magnetic resonance (NMR) spectra and nuclear spin-lattice relaxation rate T,' of 11B have been measured in superconducting polycrystalline Mg13 2 with T°"s = 39.5 K. It is shown that (T,T) (- 1) and the Knight shift K, are independent of temperature and nearly isotropic above 1. Both of these quantities are decreased gradually in going to the superconducting state. According to NMR data the density of states near the Fermi level is flat at the scale of about 500 K. Some conclusions on the orbital content of the density of states at the Fermi level were drawn and compared with the results of the band structure calculations Полный текст |