FeG

feG is an abbreviation or stylized term that can refer to multiple distinct concepts. There is no single widely accepted definition, and its meaning depends on the domain and the conventions of the source material.

In vacuum electronics and microscopy, FEG stands for Field Emission Gun, a type of electron source that produces electrons by field emission from a sharp metal tip. FEGs offer high brightness and a narrow energy spread, enabling high spatial resolution in scanning electron microscopes (SEMs) and transmission electron microscopes (TEMs). They require ultrahigh vacuum conditions and stable power supplies, and tip conditioning is important for maintaining performance. Compared with thermionic emitters, FEGs are more sensitive to contamination and can be more demanding to operate.

In materials science, FeGe (iron germanide) is an intermetallic compound composed of iron and germanium. It crystallizes in a B20-type structure and is studied for its magnetic properties, including nontrivial spin textures such as helimagnetism and skyrmion lattices under certain temperatures and magnetic fields. Research on FeGe often addresses potential applications in spintronics and fundamental magnetism.

Other uses of the form feG/FEG include acronyms in branding, organizations, or shorthand in texts; these are not standardized and require source-specific clarification. Because the term is ambiguous, readers should consult domain-specific literature or glossaries to determine the intended meaning in a given context.