PMR measurements on (Ni1 −xCux)0.5Zr0.5-Hy amorphous alloys

Abstract

Spin-spin relaxation time (T2) and complementary hydrogen content (H/M), PMR spectrum width (FWHM) and spin lattice relaxation time (T1) have been measured in (Ni1 − xCux)0.5Zr0.5-Hy ternary amorphous alloys at 0 ⩽ x ⩽ 29 at.% concentrations using Carr-Purcell-Meiboom-Gill (CPMG), solid-echo and saturation recovery pulse sequences respectively.The T2 relaxation time measured by the slope of the CPMG echo train depends on both the hydrogen and Cu content. The dependence can be attributed to the change of correlation time and not to the change of activation energy or local field. The measurements were made in the ‘motional narrowing’ state; consequently our Eaand τ∞ quantities are averaged to the diffusional motion of protons taking part in this process.The extrapolated amplitude of the echo train measured on the alloy-hydrogen system and normalized to the same quantity in water, gives the value of proton magnetization in thermal equilibrium, that is the hydrogen content free from any perturbing effects. The hydrogen content measured by CPMG echo train has turned out to be systematically smaller than that measured by weight increase.