Introduction Alloys are traditionally made from one or two principal elements, with additional elements in dilute concentrations, chosen to make the material suitable for a given application. Complex Concentrated Alloys or High Entropy Alloys have a greater number of principal elements (3-5 or more). If we use a definition of a principal element as having a concentration between 5 – 75 at% for setting up a composition space to explore experimentally, the number of possible alloys grows quickly as more elements are added. Creating a family of test alloys using composition steps of 5% yields 153 possible combinations for three elements and almost 4,000 for five elements. These are too numerous to explore one at a time in any practical way. Co-deposition by magnetron sputtering is a simple and flexible approach to make alloys with arbitrary concentrations. Gradient combinatorial sputtering provides samples that can be used to screen large numbers of possible compositions quickly. The goal of this application note is to convey a method we’ve used to make such combinatorial thin films.
