Influence of Ar-impurities on the wettability of IBS-deposited Y2O3 thin films

Highlights: • The hydrophobicity of IBS Y₂O₃ films was tested for different sputter parameters. • The residual Ar-content of the film plays a decisive role for the hydrophobicity. • Higher O to Y ratio improves the hydrophobicity. • Y₂O₃ terminated Y₂O₃:SiO₂ nanolaminates are hydrophobic. The wettability and the control of the contact angle of surfaces are important for various applications. Materials with a water contact angle less than or greater than 90 deg are hydrophilic or hydrophobic, respectively. Most of the binary oxides are hydrophilic, but oxides of rare earth metals and metal atoms with low electronegativity have hydrophobic surfaces. Yttria is one of the materials predicted to have hydrophobic properties. In this work, we investigated the wettability of ion-beam-sputtered Yttria thin films. The measured water contact angles were between 67° and 96°. The concentration of the embedded argon atoms was found to influence the contact angle.