Vibrational and geometric structures of Nb3C2 and Nb3C+2 from pulsed field ionization-zero electron kinetic energy photoelectron spectra and density functional calculations
1996; American Institute of Physics; Volume: 105; Issue: 24 Linguagem: Inglês
10.1063/1.472873
ISSN1520-9032
AutoresDong‐Sheng Yang, Marek Z. Zgierski, Attila Bérces, Peter A. Hackett, Pierre‐Nicholas Roy, Ana Martı́nez, Tucker Carrington, Dennis R. Salahub, René Fournier, Tao Pang, Changfeng Chen,
Tópico(s)Copper Interconnects and Reliability
ResumoVibrational frequencies of three niobium normal modes of triniobium dicarbide neutral and cation have been determined from pulsed field ionization-zero electron kinetic energy photoelectron spectra. The niobium stretching mode has a frequency of 326 cm−1 in the neutral and 339 cm−1 in the ion. The two deformation modes have frequencies of 238 and 82 cm−1 in the neutral and a degenerate frequency of 258 cm−1 in the ion. The geometry of the triniobium dicarbide has been established by comparing the experimental spectra with theoretical calculations. The cluster has a trigonal bipyramid geometry with carbon atoms capping on each face of the metal frame. The cation cluster has D3h symmetry whereas the neutral cluster has lower symmetry resulting from a Jahn–Teller distortion. A second low-lying structure with doubly bridging carbon atoms has been identified by the calculations but has not yet been observed.
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