Počet záznamů: 1

Fundamental Issues in the Synthesis of Ferroelectric Na0.5K0.5NbO3 Thin Films by Sol-Gel Processing

  1. 1.
    0357037 - UACH-T 2011 RIV US eng J - Článek v odborném periodiku
    Chowdhury, A. - Bould, Jonathan - Londesborough, Michael Geoffrey Stephen - Milne, S.J.
    Fundamental Issues in the Synthesis of Ferroelectric Na0.5K0.5NbO3 Thin Films by Sol-Gel Processing.
    Chemistry of Materials. Roč. 22, č. 13 (2010), s. 3862-3874 ISSN 0897-4756
    Výzkumný záměr: CEZ:AV0Z40320502
    Klíčová slova: sodium-potassium niobate * pulsed-laser deposition * lead-free piezoceramics
    Kód oboru RIV: CA - Anorganická chemie
    Impakt faktor: 6.400, rok: 2010

    In contrast to films fabricated by physical vapor deposition methods, thin films of Na0.5K0.5NbO3 (NKN) made by metal alkoxide sal gel routes generally fail to exhibit polarization-electric field responses typical of a ferroelectric. This study sets out to investigate the reasons for the problems in producing sol gel NKN films by examining the thermochemistry of the gel to ceramic conversion. The NKN precursor gels displayed multiple heating DTA crystallization exotherms in the temperature range 480-550 degrees C, which are attributed to compositional segregation of NKN components. At higher temperatures, 800-850 degrees C, a heating DTA endotherm and cooling DTA exotherm are indicative of melting and recrystallization of sodium/potassium carbonate secondary phases. Additionally, repeated thermal analyses, after storage of the gel decomposition product under ambient conditions, revealed a tendency for hydration and carbonation on exposure to air.
    Trvalý link: http://hdl.handle.net/11104/0195409