CHANGE IN NUCLEAR RADIUS UPON EXCITATION FOR SN-119, SB-121, TE-125, I-127, I-129, AND XE-129 FROM MOSSBAUER ISOMER SHIFTS

The ratio δR2R2 for two nuclei can be obtained by comparing the measured isomer shifts for isoelectronic compounds of the two elements. Such a determination is fairly insensitive to the absolute value of the electron density at the nucleus. These ratios have been found sequentially for Sn119, Sb121, Te125, I127,129, and Xe129. Taking δR2 for Sn119 to be 2.4×10-4, absolute values of δR2R2 for remaining nuclei have been found. The values are -14.6×10-4, 1.9×10-4, -4.8×10-4, 6.2×10-4, and 0.55×10-4 for Sb121, Te125, I127, I129, and Xe129, respectively. These values overlap those obtained directly by our electron-density calibrations, done individually, although they are different in some cases from earlier determinations. These results also supply a consistent set of values for the isomer shift per 5p or 5s electron for all five elements. © 1969 The American Physical Society.