GROWTH AND ELECTRONIC-STRUCTURE OF THIN EPITAXIAL PD AND CO FILMS ON W(100)

Pd and Co films deposited on a W(100) surface were studied with reflec tion high-energy electron diffraction, Auger electron spectroscopy, an d ultraviolet photoemission spectroscopy. The films grow initially pse udomorphic. At a critical coverage of 2.4 ML suddenly (<11(2)over bar 0>) oriented hcp islands form. These hcp islands have a pronounced nar row valence-band feature close to the Fermi edge, which can cause ferr omagnetism. At elevated temperatures the islands become very large and three-dimensional alloying occurs above 600 K for Pd and 400 K for Co . In Pd films are interface alloy forms around 500 K.