Editing Field electron emission (section)

==== Introduction ====
Fowler–Nordheim-type equations, in the ''J''–''F'' form, are (approximate) theoretical equations derived to describe the local current density ''J'' emitted from the internal electron states in the conduction band of a bulk metal. The ''emission current density'' (ECD) ''J'' for some small uniform region of an emitting surface is usually expressed as a function {{nowrap|''J''(''φ'', ''F'')}} of the local work-function ''φ'' and the local barrier field ''F'' that characterize the small region. For sharply curved surfaces, ''J'' may also depend on the parameter(s) used to describe the surface curvature.

Owing to the physical assumptions made in the original derivation,<ref name="Fowler1928"/> the term ''Fowler–Nordheim-type equation'' has long been used only for equations that describe the ECD at zero temperature. However, it is better to allow this name to include the slightly modified equations (discussed below) that are valid for finite temperatures within the CFE emission regime.