OBSERVATION OF THE GOLD-TUNGSTEN INTERFACE BY FIELD-ION MICROSCOPY

The interface of gold films deposited on tungsten substrates has been investigated using a liquid nitrogen cooled helium-field ion microscope. Gold films were prepared by vapor deposition on field evaporated tungsten specimens at 78 K and subsequently heated at different temperatures, up to about 1300 K. Similarity with the arrangement of underlying tungsten atoms on high index planes, for gold atoms belonging to the first interfacial monolayer, observed at low temperatures, agrees with previous models based on work function measurements. Substrate structure alterations after selective field desorption of gold film have also been observed.