Neutron scattering experiments on gadolinium

Neutron scattering experiments on gadolinium have been carried out on single crystal specimens highly enriched in 160Gd. The spin wave dispersion relations have been determined in the three principal a-, b-, and c-directions at 78 °K and at several elevated temperatures along the c-direction. The form factor has been measured for all (hk0) reflections out to sin θ/λ = 1.275 and for (h0l) reflections out to (1.04). The data deviate markedly from the Hartree-Fock calculation of Blume, Freeman and Watson. It is indicated that the metallic 4-f wave functions must be substantially different in the metal than in the free ion.