Note:
In general, such deposits are obtained at pressures of $<100\text{kPa}$ in the temperature region $600-1300\text{K}$ 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 $0.01$ to $0.5\text{μ}\text{m}$ in diameter and up to $10\text{μ}\text{m}$ 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.