Untitled research work

The principles and characteristics of a field ion microscope, a field emission microscope and an atom-probe field ion microscope are described.The resolving power of the field ion microscope is demonstrated by imaging the geometrical arrangments of individual atoms at the W-Ga, W-In and W-Sn interfaces.The observed results indicate that the Ga, In and Sn atoms in contact with four W atoms, which occupy W lattice sites, form a pseudomorphic monolayer and they are strongly bound to the W surface.A field ion microscope can be operated as a field emission microscope.The field emission microscopic observation has revealed that the work function takes its maximum value when the W surface is covered with the pseudomorphic monolayers of Ga, In and Sn.The applicability and the limitation for the field ion microscopy are discussed in comparision with the other surface research techniques.(J.Cryst.