Equiatomic intermetallic compounds YTX (T = Ni, Ir; X = Si, Ge, Sn, Pb): a systematic study by ⁸⁹Y solid state NMR and ¹¹⁹Sn Mössbauer spectroscopy.
The equiatomic TiNiSi type tetrelides YTX (space group Pnma) with T = Ni, Ir and X = Si, Ge, Sn, Pb were synthesized from the elements by arc-melting or via high-frequency-melting of the elements in sealed niobium ampoules. All samples were characterized by powder X-ray diffraction using the Guinier technique. The structures of YNiGe, YNiPb, YIrSi, YIrGe, and YIrSn were refined from single crystal X-ray diffractometer data. The YTX tetrelides are characterized by a three-dimensional [TX] network that consists of puckered T3X3 hexagons with T-X distances in the order of the sums of the covalent radii. YIrSi and YIrGe show a reverse occupancy of the T and X sites with respect to the remaining YTX compounds, which is most likely a size effect. Solid state NMR studies reveal the sensitivity of (89)Y Knight shifts to electronic structure details. A monotonic dependence on the tetrelide Pauling electronegativity is observed in addition. The stannides YTSn (T = Ni, Rh, Ir, Pt) were further characterized by (119)Sn Mössbauer spectroscopy. They show single signals that are subjected to quadrupole splitting. Comparison of the isomer shifts with the whole series of YTSn stannides gives no hint of obvious correlations as a consequence of the valence electron count but reveals a systematic decrease with atomic number within a given group.
Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany. pottgen@uni-muenster.de.
Christoph
C
Höting
Hellmut
H
Eckert
Frank
F
Haarmann
Florian
F
Winter
Rainer
R
Pöttgen