AND

The Mossbauer effect in the 100-keV 2+ ~ 0+ transition in W182 was observed with dilute t~ngsten in iron alloy absorbers with concentrations from 0.5-5.0 at.%W at 4.2°K. From the Zeeman spectra In external longitudinal magnetic fields, the g factor of the first excited 2+ state was found to be O.~2±0.O~, and the hyperfine field at tungsten nuclei in iron was found to be-708±25 kOe. The hyperfine Interaction for Fe57 in these alloys was also measured, and the results are compared with measurements on alloys of Fe with other 5d impurities and with neutron diffraction measurements. I. INTRODUCTION was to resolve the discrepancy in values obtained by NMR and Mossbauer techniques and by perturbedT HE large magnetic fields in.duced at t~e nuclei?f angular correlation following Coulomb excitation. Themagnetic and nonmagnetIc ato~s dIss.olved. In latter 1 called the "impact technique, " utilizes theferromagnetic metals have been the subject of Int~nslve Coul;mb excitation to recoil-implant the W nuclei into experimental investigations by a variety of technIques. the Fe host. Such measurements thus follow the disThe result has been a growing systematics of such ruptive entrance of the excited nucleus into ~~e backinghyperfine fields as well as some insight into their origin. foil and it is not clear that the local condItIon of theWith this understanding has come an increased use for lat~ice is comparable to the static conditions as in the these fields for the measurement of the magnetic hyper other experiments. In fact, recent measurements2,3 byfine interactions of short-lived excited nuclear states the impact technique of the hyperfine interaction of th