FCE has been shown to be reversible, demonstrating the fact that the electrons are moving rather than thermomigration or sublimation.
The migration occurs due to the electronic wind force experienced by the metallic adatom.
[1] The electromigration occurs at a critical power dissipation
[2] This leads to Electromigrated Nanogaps which hold immense potential for sensing applications, exploiting the quantum tunneling effect.
Thermal runaway can occur when the neck is narrower than about 20 nm.