In general, such deposits are obtained at pressures of <

in the temperature region

-

on metals such as iron, cobalt or nickel. Typical filaments consist of a duplex structure,
a relatively
oxidation-resistant skin surrounding a more easily oxidizable core, with a metal particle located
at the growing end of the filament. They generally range from

to

in diameter and up to

in length. In some systems, the metal particles are located in the middle of the filaments,
and there are also examples where several filaments originate from a single particle.
The filaments may be produced in different conformations, such as helical, twisted
and straight.