THE EFFECTS OF TEMPERATURE AND BISMUTH IMPURITIES ON PREFERRED ORIENTATIONS OF COPPER AND SILVER ON AMORPHOUS SILICA

The effects of temperature and bismuth impurities on preferred orienta tions of copper and silver on amorphous silica are studied for the tem perature range 74 to 98% of the melting temperature of the metal phase s. It is shown that, at low temperatures, two preferred orientations e xist for both pure metals, which have either the (111) or the (100) pl ane of the metal phase parallel to the silica substrate. Increasing th e temperature results in a gradual elimination of the (100) preferred orientation, such that at 98% of the melting temperature, only the (11 1) orientation remains present. On the other hand, the addition of bis muth is observed to have a stabilizing effect on the (100) orientation , such that this orientation occurs even at the highest annealing temp eratures. These results will be discussed in terms of the interfacial energy curves for metal/amorphous silica interfaces.