Title: phase domain
Long Title: IUPAC Gold Book - phase domain
DOI: 10.1351/goldbook.PT07286
Status: current

Definition
Region of a material that is uniform in chemical composition and physical state.

Notes
1) A phase in a multiphase material can form domains differing in size.
2) The term 'domain' may be qualified by the adjective microscopic or nanoscopic or the prefix micro- or nano- according to the size of the linear dimensions of the domain.
3) The prefixes micro-, and nano- are frequently incorrectly used to qualify the term 'phase' instead of the term 'domain'; hence, 'microphase domain', and 'nanophase domain' are often used. The correct terminology that should be used is phase microdomain and phase nanodomain.

Related Terms
- micro: https://goldbook.iupac.org//terms/view/M03894
- nano: https://goldbook.iupac.org//terms/view/N04082

Source
- PAC, 2004, 76, 1985. 'Definition of terms related to polymer blends, composites, and multiphase polymeric materials (IUPAC Recommendations 2004)' on page 2001 (https://doi.org/10.1351/pac200476111985)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/PT07286/html
- json: https://goldbook.iupac.org/terms/view/PT07286/json
- xml: https://goldbook.iupac.org/terms/view/PT07286/xml

Citation: Citation: 'phase domain' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.PT07286
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.
Collection: If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .
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.
Accessed: 2026-05-08T23:33:47+00:00