ISOMER SHIFT OF FE57 IN TRANSITION METALS UNDER PRESSURE.

Isomer shifts of Fe57 in several transition metals were measured as a function of pressure up to nearly 300 kbar. The host metals studied were V, Cr, Co, Ni, Nb, Mo, Pd, Ta, W, Pt, and Au. The data are discussed in terms of the volume dependence of 1 the density at the nucleus from 4s-like conduction electrons and 2 the density at the nucleus from 3s core electrons which are shielded by the 3d-like conduction electrons. Results of a previous paper regarding amount of 4s character, n-s, and amount of 3d character, n-d, in the iron impurity atom, are used. The data are shown to be consistent with 1 n-s decreasing or n-d increasing, or both as one goes through each transition metal series toward more d electrons of the host and 2 n-s decreasing or n-d increasing, or both, as pressure is applied to the host metal. The degree of the effect 2 is shown to be related to the calibration constant of the isomer shift. Author