Work to date on multilayer tunneling systems has resulted in the direct observation of single-electron tunneling effects in ultra- small-capacitance systems containing small (10-100 Angstrom diam.) metal particles. Measurements have also been made of the perpendicular resistivity of thin films. Research will be continued on the use of lithographic methods to permit better control of the fabrication of ultra-small metal and semiconductor dots. More complex structures can then be created, which may allow the observation of high-frequency phenomena akin to the AC Josephson effects. The now-established technique for measuring perpendicular resistivities will be applied to selected multilayer systems, especially Fe-based systems with anomalous magnetotransport properties.
