The sticking of magnesium on ω-tricosenoic acid multilayers deposited by the langmuir-blodgett technique

Abstract

Results are presented illustrating the curious behaviour of condensing magnesium films on thin Langmuir-Blodgett layers formed of ω-tricosenoic acid. At room temperature thin layers of magnesium (less than 100 nm) are readily condensed on a layer comprising more than 8 monolayers. However, for a smaller number of monolayers, progressively less magnesium is seen to stick to the surface; the discussions given indicate this to be related to the magnesium's sensitivity to changes in surface morphology. This strange sticking behaviour has severe implications on the fabrication of thin tunnel junctions. An example of this is presented showing the importance of the electrode geometry used in these structures. The quality of deposition of ω-tricosenoic acid is considerably reduced when “cross-like” electrode structures are used, making it virtually impossible to fabricate thin insulating junctions using this form of electrode configuration. This may also be one of the major reasons for poor reproducibility or junction failure using this type of configuration.