H-1-NMR SPECTRA AND H-SITE OCCUPANCY IN ZR0.5CUYNI0.5-YH1 METALLIC GLASSES

Proton magnetic resonance spectra of Zr0.5CuyNi0.5-yH1 metallic glass samples with 0 less-than-or-equal-to y less-than-or-equal-to 0.3 were measured in the temperature range 77 K to 400 K and at 8, 28-5, 87.6 a nd 88.5 MHz frequencies. The data of the free-induction decay (FID) si gnal were compiled and Fourier transformed by a SMIS NMR spectrometer. The temperature dependence of the line shapes shows three distinctly different features: (i) in the temperature range 400 K to 270 K the sp ectrum is a motionally narrowed Lorentzian line; (ii) in the temperatu re range 270 K to 140 K the spectrum consists of a narrow Lorentzian c omponent and a substantially wider Gaussian one; (iii) in the temperat ure range 140 K to 77 K, the spectrum is a ''two-peaked'' line. The di stance between the two peaks (splitting) was found to be independent o f the temperature and the frequency, that means that the low-temperatu re spectrum is probably the Pake doublet of hydrogen pairs. From the a nalysis of the splitting of the Pake doublet, a proton-proton distance of 0.167 nm was estimated. This distance corresponds to a transition metal mediated hydrogen pairing.