Author ORCID Identifier

Date Available


Year of Publication


Degree Name

Master of Materials Science and Engineering (MMatSE)

Document Type

Master's Thesis




Chemical and Materials Engineering

First Advisor

Dr. Matthew Beck


The exact surface configuration of scandate cathodes has been a point of contention for the materials community for a long time. Without proper understanding of it and the related structures and emission mechanisms, scandate cathodes remain patchy and unreliable emitters. Thus, density functional theory techniques were applied to various potential surface arrangements and found that there are several low-energy surfaces with low work functions that incorporate a scandium interlayer between tungsten and oxygen or otherwise have a scandium-on-tungsten structure. Furthermore, it was discovered that adding a monolayer of scandium directly to a tungsten surface is surprisingly favorable, thermodynamically. While none of the test surfaces match the properties or compositions of real scandate cathode surfaces, they shine a light on the previously-unexplored phenomenon of this scandium monolayer effect which runs counter to commonly-understood metallurgical principles.

Digital Object Identifier (DOI)

Funding Information

This work was financially supported by the Defense Advanced Research Projects Agency (DARPA) Innovative Vacuum Electronics Science and Technology (INVEST) program, under grant number N66001-16-1-4041.