Fig. 8
From: Wetting and adhesion properties of quasicrystals and complex metallic alloys
Left sketch of the successive heat treatments applied to three samples as indicated in the upper inset. Right values of the contact angle θ of water measured at the positions in time shown by numbers in the left hand side part of the figure. Observe that the values of θ are large only after a long time elapsed in ambient air, but reduce to the value of (thick) alumina immediately after heat treatment and before a contamination layer has enough time to form again