Topography of thin films containing Ni-Ga intermetallic compounds formed on GaN(0001)

Abstract

Studies, carried out in situ by scanning tunneling microscope (STM), on the topography of thin films containing Ni-Ga intermetallic compounds are presented in this report. It is shown that conditions of the film preparation influence size and shape of 3-D formations constituted of the compounds. The films are formed in two ways. The first one in which pre-deposited at room temperature Ni film is annealed at 650 oC, and the second one where Ni is evaporated directly onto the substrate kept at 650 oC. Films obtained by using the second procedure should be more suitable for catalytic applications. Grains of the compounds formed in these films do not show tendency for coalescence and are more strongly dispersed in contrary to the grains formed in the films obtained by using first procedure.