Using Murphy-Good Plots to Interpret Field Emission Current-Voltage Data

This paper focuses on one small but significant part of a long-term project that aims to improve the interpretation of measured field electron emission (FE) current-voltage [I
m
(V
m
)] data, and (later) the formulation of FE theory. A new form of FE I
m
(V
m
) data-analysis plot––the so-called "Murphy-Good" (MG) plot"––has recently been introduced, within the general framework of the prevailing "smooth planar metal-like emitter" methodology. This new plot form, and the reasons for its introduction, are discussed. It is shown that the MG plot can perform all the functions that the traditional (90-year old) Fowler-Nordheim plot does, but in addition yields relatively precise results for the characterization parameter "formal emission area". It can be argued that, certainly in scientific contexts, the use of MG plots could usefully replace the use of FN plots.