This project is part of the National Research Network (NFN) HIGH-PERFORMANCE BULK NANOCRYSTALLINE MATERIALS: PHYSICS OF SYNTHESIS AND PROPERTIES. This project part of the NFN aims at the cluster-synthesis of nanocrystalline metals and alloys and the control of their properties by electrical field-induced modifications of the charge carrier density in the interface region. The project will focus on charge-controlled magnetism, a topic from which a substantial added value to one main goal of the NFN, namely the development of novel kinds of nanophase magnetic materials, can be expected. The concept of charge-induced property tuning could be demonstrated recently by making use of nanocomposites of nanocrystalline metals and liquid electrolytes. Owing to the high surface-to-volume ratio of nanoscale metals, voltage-induced formation of electrochemical double layers gives rise to a high fraction of interfacial space-charge regions which results in a reversible change of the overall physical properties of the metal. Based on our recent pioneering studies on this topic, the project aims at an understanding of the microscopic processes which are relevant for charge-induced property tuning.