  An important parameter used to characterize large-area field electron
emitters (LAFEs) is the characteristic apex field enhancement factor
{\gamma}_C. This parameter is normally extracted from the slope of a
Fowler-Nordheim (FN) plot. Several years ago, the development of an "orthodoxy
test" allowed a sample of 19 published FN plots relating to LAFEs to be tested,
and it was found that about 40% of the related papers were reporting spuriously
high values for {\gamma}_C. In technological papers relating to LAFE
characterization, common practice is to pre-convert the measured voltage into
an (apparent) value of macroscopic field before making and analyzing a FN plot.
This paper suggests that the cause of the "spurious-FEF-value" problem is the
widespread use of a pre-conversion equation that is defective (for example, not
compatible with ordinary electrical circuit theory) when it is applied to
so-called "non-ideal" field emission devices/systems. Many real devices/
systems are non-ideal. The author argues that FN plots should be made using raw
experimental current-voltage data, and that an orthodoxy test should be applied
to the resulting FN plot before any more-detailed analysis, and that (in view
of growing concerns over the reliability of published "scientific" results)
reviewers should scrutinize field emission materials-characterization papers
with enhanced care.
