Tailoring of optical, mechanical and surface properties of high-entropy ceramic thin films

In this article we show the optical, mechanical and surface properties change depending on the Hf-Zr-Ce-Y-O thin film composition. Hf4Zr4CeY2O21shows up to three times higher hardness compared to binary HfZrO4oxide and up to 50% higher hardness compared to cubic ZrO2 and HfO2due to the solid solution hardening effect. Equimolar film exhibit a high transmittance >85% and high hydrophobicity with the water contact angle ≈106°. Variation of the elemental composition in Hf-Zr-Ce-Y-O is allows to simultaneously tune mechanical and wetting properties for the optimum configuration depending on the application.