Novel duplex antimicrobial silver films deposited by magnetron sputtering

Novel duplex silver films, exhibiting antimicrobial behaviour, have been produced by magnetron sputtering and studied using high-resolution scanning electron microscopy. These films were grown under deposition conditions in which the gas composition, process pressure and input power were varied. It was determined that biologically active films had a nanocrystalline structure consisting of loosely held particles with a grain size of the order of 15nm. The importance of oxygen in the sputtering environment and the resultant microstructure are discussed to explain the unique antimicrobial properties of these silver films.