MAGNETIC 4D SYSTEMS STUDIED BY IMPLANTED IONS

By application of the perturbed gamma-ray distribution method followin g heavy-ion reactions and recoil implantation techniques, we have foun d an experimental way of producing and investigating magnetic 4d state s in metals. Strong 4d magnetism has been found for 4d ions in alkali metal hosts and in Pd hosts. In alkali metals, 4d ions reflect the phe nomena of well-defined ionic ground states, orbital magnetism, mixed v alence, and crystal field splittings smaller than the LS coupling. Mag netic 4d states in alkali metals cannot be described by one-electron a pproaches based on Anderson-type models, but requires an analysis in t erms of many electron ionic configurations exhibiting basic features c ommon to the physics of stable and unstable f states in metals. In con trast, the local moment formation of 4d and 3d ions in Pd is governed by inter-atomic interactions of the magnetic d states with host d-band electrons, giving rise to spin magnetic behavior of the 4d impurity a nd to strong spin polarizations of the 4d electrons of the Pd host. Th us, the magnetism and electronic structure of 4d ions in metals exhibi t qualitative differences in alkali metal hosts compared to Pd. The ex istence of magnetic 4d systems strongly depends on the 4d ion species and the host matrix, and on spin fluctuation rates or the correspondin g Kondo temperatures. The results can be directly compared to theoreti cal work and also to the magnetic behavior of 3d ions in sp metal sts and in hosts with d-band electrons.