Nature of incommensurate phases in real systems

    Research output: Chapter in Book/Report/Conference proceedingChapter

    3 Citations (Scopus)


    Features of both incommensurate phases and incommensurate-to-commensurate transitions in K 2SeO 4and Ba 2NaNb 5O 15 have been analyzed on the basis of the Ginzburg-Landau theory, in which only the translation symmetry is taken into account. When only three higher-order distortion waves as well as the first-order wave are included, the theory reproduces incommensurate features obtained experimentally. This is an indication that the incommensurate phases in real systems never have the lowest free energy and are then characterized as an non-equilibrium state. Because the discommensuration interacts with structrual defects, the non-equilibrium state should be realized as a result of an interaction between the discommensuration and the defect involved in real systems.

    Original languageEnglish
    Title of host publicationFerroelectrics
    Number of pages17
    Publication statusPublished - 1997



    • Ginzburg-Landau theory
    • Incommensurate-to-commensurate transition
    • Non-equilibrium state

    ASJC Scopus subject areas

    • Materials Science(all)
    • Electronic, Optical and Magnetic Materials
    • Condensed Matter Physics

    Cite this

    Koyama, Y., & Arao, M. (1997). Nature of incommensurate phases in real systems. In Ferroelectrics (1-4 ed., Vol. 203, pp. 389-405)