Sup (29) Si nuclear magnetic resonance spectra of transition metal silicides.

This memorandum explores the potential utility of NMR spectroscopy for the characterization of transition-metal silicides. Sup (29) Si chemical shielding parameters are derived from sup (29)Si NMR spectra of 24 silicides of Group IVB, VB, VIB and VIII metals. The isotropic shifts of these silicides span the range from -1650 ppm to +925 ppm, relative to TMS, and have shielding anisotropies -250 ppm to +335 ppm; these extremes are approximately 10 times as large as those of organosilicon and silicon oxide compounds. For silicides of Ti, Zr, Nb, Cr, Mo, W, Rh, Ni, Pd, Pt, and Cu, the chemical shielding interaction is sufficiently larger than the extraneous spectral broadening to allow detection of multiple phases owing to different crystal structures and local stoichiometry differences.