Observation of size dependent orbital magnetism of single Fe impurity in nanocrystalline Pb hosts

Abstract

Employing the time differential perturbed angular distribution (TDPAD) technique we have investigated the local magnetism of single Fe impurity in nanocrystalline Pb matrices, by measuring the local susceptibility and spin relaxation rate of 54Fe nuclei. Compared to the nonmagnetic behavior of Fe in bulk Pb host, characterized by independent local susceptibility χloc(T), the magnetic response of Fe in the nanocrystalline samples with particle size of 10 nm and below exhibit Curie-Weiss like χloc(T) with positive slope, indicating the presence of large orbital magnetic moment on the Fe impurity. The orbital moment of Fe has been estimated to be ∼ 1 µB for 6 nm nano-Pb. Further investigations are being carried out to understand the emergence of orbital magnetism of Fe in nano-Pb.