Study of Molecular Patterns in the Field Emission Microscope

Abstract

Field emission patterns of organic dye molecules such as phthalocyanine or flavanthrene show improved stability when the tip temperature is lowered. No prior contamination or buildup is necessary for the production of typical quadruplet or doublet patterns. Upon heating or ion bombardment the molecule patterns may disappear in several distinct steps of size and intensity. On the average 13 phthalocyanine or 2 flavanthrene molecules must strike the tip to produce one pattern. These observations suggest that the substances studied here evaporate and arrive at the tip as polymerized units consisting of two to six molecules. A mechanism for image formation is proposed.