An accurate and simple method of measuring nuclear spin lattice relaxation at low temperatures, applied to 60CoFe

Pulsed eddy current heating of a thin Fe foil, cooled by direct contact with the He within the mixing chamber of a dilution refrigerator, is used to measure the nuclear spin lattice relaxation of dilute 60Co in Fe. This simple method which gives the true domain relaxation - avoids several difficulties present in other types of experiments, as is shown in a comparison of methods. The field dependence of the Korringa constant is measured between 0 and 10 kG; above 1 kG it is found to approach exponentially a limiting value of 2.27 sK. (Auth.)