Gyromagnetic Ratios of Fe and Ni

Abstract

two cases can be distinguished in two ways: by the existence or nonexistence of a transient region of M s (t)~-fi and by the magnetic field dependence of M z {t) for large t. In either case, it is possible to compute C and thus determine r for the paramagnetic ion independent of a paramagnetic resonance experiment. In the case of diffusion-limited relaxation, it is also possible 1

Accurate Determination of the Electron Spin Polarization In Magnetized Iron and Nickel Foils for Møller Polarimetry

“…These data were taken from compilations in two papers 6 by G. Scott in 1962 [40] and Meyer and Asch in 1961 [44]. For reference, the data included in these compilations comes from [42,47,48,49,50]. The final two measurements done by G. Scott are by far the most precise.…”

“…It is clear given the fit probability of 0.004 and from discussions of how the uncertainties were determined, that the error bars do not in all cases reflect the actual systematic error, which, in at least some of the measurements, is underestimated. The most accurate measurements were made by Scott, who without stated justification, concludes that his most recent measurement of g = 1.919 ± 0.002 on a prolate ellipsoid sample is the best value to use for iron [50,40] even though he measured g = 1.917 ± 0.002 on a cylindrical sample using the same apparatus. It is likely that he regarded the ellipsoid-shaped sample more accurate because of the uniformity of the internal magnetic field this shape produces.…”

“…• Scott cylinder 99.94% with primary impurities O(0.04%), C(0.005%), N(0.004%), S(0.003%) and Ni(0.0015%) [47] • Scott ellipsoid, 99.89% with primary impurities Ni(0.05%), Si(0.01%), O(0.005%), Co(0.005%) [50] • Meyer 1957, 99.9% with primary impurities Mn(0.042%), S(0.029%), Si(0.02%) [49] Scott carefully measured the effect of mixing the ferromagnetic elements Fe, Co and Ni and since their g values are all within 5% of each other trace amounts of impurities (<1%) from of Ni and Co in Fe will have negligible effect on the value of g (see Fig 1 of [53]). There is little guidance in the literature for the effect of trace amounts of O, Mn, N, C and S on g for Fe making it difficult to set the scale for such errors.…”

“…He published three papers documenting the low-field behavior of g for nickel and iron and alloys of the two [71,58,72]. In 1960, he found that this low-field behavior was due to a systematic error in his measurement technique [50]. After improving the technique and re-measuring, he concluded that, in fact, g is independent of applied field for Ni and Fe over the range of fields he was measuring.…”