ABSTRACT
Composite materials consisting of metallic clusters or crystals of nanometer dimension embedded in an insulator host can exhibit special optical, electrical, magnetic, and mechanical properties that may be used in various technological applications.1-8 For example, metal nanocrystals embedded in insulating materials offer enhanced mechanical properties, making them promising candidates for use in machine tools.9-14 The search for materials with enhanced hardness is driven by both the scientific curiosity of researchers to explore the possibilities of synthesizing a material whose hardness could approach or even exceed that of diamond and the technical importance of hard materials for wear protection, e.g., of machine tools. The importance of hard-wear protective coatings for machining applications is illustrated by the fact that today more than 40% of all cutting tools are coated by wear-resistant coatings and the market is growing fast. Wear-resistant hard coatings for high-speed dry machining would allow the industry to increase the productivity of expensive automated machines and to reduce the high costs presently associated with the use of environmentally hazardous coolants.
