PNNL

Abstract

Thin film nanolaminate materials can exhibit physical, optical and mechanical properties very different and superior to those of single layer counterparts. In the past fifteen years, hard coating, optical and electrical device technologies have advanced beyond the use of single layer coatings with the development of nanoscale compositionally modulated coatings, or superlattices, nanolaminates and nanocomposites. A typical nanolaminate consists of hundreds to thousands of nm-scale layers with alternating compositions and/or crystalline phases. It is possible to engineer the electrical and mechanical properties by choice of layer thicknesses and compositions. Typical layer thicknesses are between 2 and 100 nm. We report of three types of nanolaminate coatings: (1) aluminum nitride/silicon nitride optical superlattice for abrasion protection of optical windows, (2) aluminum/copper structural nanolaminates using a roll-to-roll process and (3) advanced thermoelectric nanolaminates. All nanolaminate coatings were deposited by DC and RF reactive magnetron sputtering. The aluminum nitride/silicon nitride nanolaminate had layer thicknesses of 2 nm and exhibited a nanohardness of 35 GPa. The aluminum/copper nanolaminate had layer thicknesses of 1.5 nm and a hardness near 6.5 GPa and is being developed for lightweight optics for space applications.