Formation of high entropy alloy films on various substrates via pulsed laser deposition using a rotating multicomponent target

Abstract

High entropy alloys (HEAs) are a groundbreaking class of materials that present a challenge to traditional alloy design principles by combining multiple elements in near-equal proportions, giving rise to uniquely stable formulations. These can display exceptional mechanical, thermal, corrosion-resistant or gas-barrier properties, with potential transformative applications in various industrial sectors. Depositing high entropy alloy films (HEFs) could potentially extend these benefits to large area applications for a fraction of the cost of manufacturing bulk materials, but reliable techniques for this have yet to be developed commercially. Here, pulsed laser deposition (PLD) is used to create thin films of Cantor-like HEAs on glass, aluminum, and steel substrates. This is uniquely achieved using a rotating circular target made up of pure chromium, manganese, iron, cobalt and nickel sectors, avoiding the need for a bespoke bulk HEA target. The depths of the implanted HEFs range from ∼0.1 to 1.4 μm, and the thicknesses range from ∼0.1 to 0.8 μm, dependent on the chamber pressure and the substrate type, and the HEFs are found to act as effective barriers to oxygen permeation. This work offers a simple and effective route for the large area modification of different surfaces with e.g. improved gas barrier properties.