Term: filamentous carbon https://doi.org/10.1351/goldbook.F02362 Definition: A carbonaceous deposit from gaseous carbon compounds, consisting of filaments grown by the catalytic action of metal particles. Note: In general, such deposits are obtained at pressures of 100 kPa in the temperature region 600 on metals such as iron, cobalt or nickel. Typical filaments consist of a duplex structure, a relatively @O04362@-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 µm in diameter and up to 10 µm 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. Related Terms: 1) oxidation (http://doi.org/10.1351/goldbook.O04362). Source: PAC, 1995, 67, 473. 'Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995)' on page 488 (https://doi.org/10.1351/pac199567030473) Citation: 'filamentous carbon' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.F02362 License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.