9223684 First The objective of this project is to understand the evolution of magnetism, from adatoms to clusters to thin films. Emphasis is placed on clusters and adatoms. Of interest is the minimum size required for cooperative magnetic properties. Also of interst are interparticle magnetic interactions. The result will be relevant to development of magnetic cluster media, magnetic thin-film technology, and theories of low-dimensional magnetism. Scanning tunneling microscopy and spin-polarized scanning tunneling microscopy will be used in the investigations. %%% This project will study magnetic interactions between magnetic atoms on surfaces. Groups of atoms will be built up to form clusters, and the variation of the magnetic properties of the cluster with size will be studied with atomically sensitive microscopies. The results will be relevant to the development of new magnetic media for thin film recording and general information technology. ***