O.J. Żogał

Characterization of the electronic properties of YB12, ZrB12, and LuB12 using 11B NMR and first-principles calculations

Three metallic dodecaborides, YB12, ZrB12 and LuB12, have been investigated by electric-field gradient (EFG) measurements at the boron sites using the 11B nuclear magnetic resonance (NMR) technique and by performing first-principles calculations. The NMR powder spectra reveal patterns typical for a completely asymmetric EFG tensor, i.e., an ? parameter close to unity. The absolute values of Vzz (the largest component of the EFG) are determined from the spectra and they range between 11 ? 1020?V?m?2 and 11.6 ? 1020?V?m?2 with an uncertainty of 0.8 ? 1020?V?m?2, being in very good agreement with the first-principles results. In addition the electronic structure and chemical bonding are analysed from partial densities of states and electron densities.

91Zr nuclear magnetic resonance in tetragonal ZrH2

Abstract We report on the first observation of the 91 Zr NMR signals in tetragonal phase of ZrH 2 . The Knight shift and spin-lattice relaxation time in zirconium dihydride have been measured in the temperature range 155–294 K. Their analysis is referred to the electronic structure of this material. The electron density of states N ( E F ) and character of the d orbital wave functions at Fermi level E F are discussed.

91Zr knight shift anisotropy in tetragonal ZrH2

Abstract A narrowed spectrum of 91 Zr in tetragonal ZrH 2 resulting from the use of MAS NMR technique, was observed. This, together with static spectrum, allowed to determine the Knight shift tensor components K iso = 2600 ± 20 ppm and K ax = 137 ± 10 ppm . The anisotropic part ( K ax ) is discussed in terms of some details of electronic band structure of the hydride.