Wetting of decagonal Al₁₃Co₄ and cubic AlCo thin films by liquid Pb

Abstract

Wetting of micron-sized Pb droplets on thin polycrystalline films of decagonal Al₁₃Co₄ and cubic crystalline AlCo phases is reported. The sample preparation is crucial to having Pb droplets lying on a clean surface. Decagonal and cubic films were prepared under high vacuum conditions, by sequential deposition and annealing of specific stackings of Al and Co layers of nanometre thicknesses. A 300 nm thick Pb slab was then deposited on the top of the films. Dewetting experiments were performed in situ in a scanning Auger microprobe where the surface chemistry can be monitored: the Pb slab dewets into droplets. The wetting of Pb on both substrates was found to be similar with contact angles around 45°.

Acknowledgments

The authors acknowledge the financial support of the Ministère délégué à la Recherche (Action Concertée Incitative 2000, Surfaces, Interfaces et Conception de nouveaux matériaux).