Memory effect in an incommensurate phase of barium sodium niobate

S. Mori, N. Yamamoto, Yasumasa Koyama, Y. Uesu

    Research output: Chapter in Book/Report/Conference proceedingChapter

    3 Citations (Scopus)

    Abstract

    In order to investigate a microstructure giving rise to a memory effect in the incommensurate phase of barium sodium niobate (BSN), in-situ observations of a tetragonal-to-incommensurate phase transition were made in both non-annealed and annealed samples by means of a transmission electron microscope. Note that only the annealed sample exhibits the memory effect found in the incommensurate phase of BSN. In a case of the non-annealed sample, when the sample is cooled from the high-temperature tetragonal phase, a region having a plate-shaped contrast, a microdomain structure, appears around 260 °C, together with a region having the dot-shaped contrast. From the examination of the contrast reverse in the satellite dark field images with different reflection spots, the microdomain structure is understood to be composed of two 1q ferroelastic microdomains and can be regarded as the 2q tetragonal state in an average structure. The region of the dot-shaped contrast is, on the other hand, the 1q orthorhombic state. On further cooling in the incommensurate phase, the microdomain structure disappears while large 1q ferroelastic domains are formed around 220 °C. In the annealed sample, however, the microdomain structure never disappears even at room temperature and appears reversibly during the heating and cooling processes. From these experimental results, the appearance of the memory effect is understood to originate from the stabilization of the microdomain structure regarded as the 2q state.

    Original languageEnglish
    Title of host publicationFerroelectrics
    EditorsB.A. Strukov, L.N. Rashkovich, Y. Ishibashi, Y. Uesu
    PublisherGordon & Breach Science Publ Inc
    Pages105-113
    Number of pages9
    Volume169
    Edition1 -4 pt 1
    Publication statusPublished - 1995
    EventProceedings of the 1994 5th Russian-Japanese Symposium on Ferroelectricity. Part 2 (of 2) - Moscow, Russia
    Duration: 1994 Aug 221994 Aug 27

    Other

    OtherProceedings of the 1994 5th Russian-Japanese Symposium on Ferroelectricity. Part 2 (of 2)
    CityMoscow, Russia
    Period94/8/2294/8/27

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    ASJC Scopus subject areas

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

    Cite this

    Mori, S., Yamamoto, N., Koyama, Y., & Uesu, Y. (1995). Memory effect in an incommensurate phase of barium sodium niobate. In B. A. Strukov, L. N. Rashkovich, Y. Ishibashi, & Y. Uesu (Eds.), Ferroelectrics (1 -4 pt 1 ed., Vol. 169, pp. 105-113). Gordon & Breach Science Publ Inc.