Existence and Stability of Magnetic3dMoments in Noble- and Transition-Metal Hosts

Mainly based on data for local susceptibilities and $3d$ spin rates of dilute Fe ions in many metals, we conclude that the existence and stability of Fe, Co, and Ni moments in Cu, Ag, Au, and certain transition-metal hosts are governed by impurity-$3d$ host-$d$ electron interactions. As the leading contribution to moment stability we propose ferromagnetic-$3d$ host-$d$ exchanges which in certain hosts successfully suppress spin fluctuations arising from antiferromagnetic $d-sp$ exchanges. All host-dependent trends of moment stability of Mn, Fe, Co, and Ni ions in metals are consistent with our proposal.