BA DEPOSITION ON SI(100)2X1

The Ba deposition on Si(100)2 x 1 at room temperature has been investigated by LEED, AES, TDS, EELS and work function measurements. Ba grows, though disordered, layer by layer with a constant sticking coefficient. Barium on Si(100)2 x 1 gives rise to two adsorption states which exhibit relatively high binding energy for THETA less-than-or-equal-to 2 ML, a strong Ba-Si ionic interaction and relatively low binding energy for THETA > 2 ML where the Ba overlayer has a metallic character. Heating of the Ba-Si interface at T < 700-degrees-C promotes Ba-Si interaction, probably with a tendency to form silicide compounds. Higher temperatures cause the appearance of the 2 x 4, 2 x 1 and 2 x 3 diffraction patterns.