Orbital Magnetism in Transition-Metal Clusters: From Hund’s Rules to Bulk Quenching

TLDR

Orbital moments of transition‑metal clusters bridge atomic Hund’s rules and solid‑state quenching. The study examines trends in orbital moments across different transition metals. Orbital moments are markedly enhanced, with small Ni clusters contributing 20–40 % of total magnetization and larger clusters showing bulk‑like quenching inside but surface enhancement, matching recent measurements.

Abstract

The local and average orbital moments <L> of transition-metal (TM) clusters are determined bridging the gap between atomic Hund's rules and solid-state quenching. A remarkable enhancement of <L> is revealed in agreement with recent measurements. In small Ni(N) (N< or =10), <L> represents (20-40)% of the total magnetization and is therefore crucial for the comparison between theory and experiment. Larger clusters (N> or =150) show nearly bulklike quenching at the interior but retain a considerable surface enhancement. Trends for different TM's are discussed.