NSF Award
9460511
This SBIR Phase I project will investigate a new phenomenon discovered recently at Ultramet while fabricating thermionic emission devices using thin films of lanthanum hexaboride (LaB6), a low work function thermionic emitter. This phenomenon, designated giant impedance transition (GIT), is represented by a large and very fast change in impedance (or resistance in DC) in response to external electromagnetic and electrostatic radiation. It should be noted that all observations of the GIT phenomenon have been extremely preliminary, obtained merely as a byproduct of the thermionic emission work being performed, with no focus having been given to the phenomenon itself. As such, much additional work is required to understand the physics of the GIT phenomenon and quantify it before proceeding to the device design stage. In this program, Ultramet will investigate the GIT phenomenon to achieve an understanding of its physics, perform quantitative analysis, and relate the behavior of the impedance change in the LaB6 deposit to its microstructure and thus, the processing technique. Ultramet will team with the Electrical Engineering Department of the University of Utah for characterization of the electrical and optical properties of LaB6 thin films produced at Ultramet. The successful completion of this effort will result in an understanding and quantification of the GIT phenomenon, as well as a direction for device design and fabrication to be pursued in follow-on work.
