{"term":{"id":"09268","title":"plasmon","longtitle":"IUPAC Gold Book - plasmon","doi":"10.1351\/goldbook.09268","code":"09268","status":"current","synonym":"<em>synonyms<\/em>: bulk plasmon, volume plasmon","definitions":[{"id":1,"text":"Excitation of valence-band electrons in a solid in which collective oscillations are generated.","notes":{"1":"Plasmon excitations are often observed as characteristic energy loss peaks associated with other peaks in the spectrum, such as those of any elastically scattered primary electrons, photoelectron peaks, Auger electron peaks, and ionization edges.","2":"Plasmons are prominent in some materials and not others.","3":"Two types of plasmon are commonly observed: bulk plasmons, associated with material remote from the surface, and surface plasmons, associated with material at the surface. When the term plasmon is used without a qualifier, the term refers to the bulk plasmon. Occasionally, interface plasmons can be observed that are associated with interfaces. Bulk plasmon energies depend on the electronic structure of the material and are roughly proportional to the square root of valence-band density. Surface plasmon energies are typically between \\(\\pu{50\\%}\\) and \\(\\pu{90\\%}\\) of bulk plasmon energies."},"links":[{"term":"characteristic energy loss","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/09315"}],"sources":["PAC, 2020, 92, 1781. 'Glossary of methods and terms used in surface chemical analysis (IUPAC Recommendations 2020)' on page 1809 (https:\/\/doi.org\/10.1515\/pac-2019-0404)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/09268\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/09268\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/09268\/plain"},"citation":"Citation: 'plasmon' 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.09268","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":"2026-04-21T05:25:45+00:00"}}