Qualitative measurement of residual carbon in wet-chemically synthesized powders

Emerson R. Camargo, Elson Longo, Edson R. Leite, Masato Kakihana

    Research output: Contribution to journalArticlepeer-review

    14 Citations (Scopus)


    Sodium niobate powders were prepared by the polymerizable complex (PC) method using a water-soluble Nb-malic acid complex and sodium carbonate. Niobium oxide pentahydrated was dissolved in hot oxalic acid (OA) solution, followed by the addition of NH3 (30%) until pH 11, precipitating niobic-acid that was added into a solution of DL-malic acid (MA) at mole ratio of [MA]:[Nb]=2:1. Na2CO3 was added in the mole ratio [Na]:[Nb]=1:1, and the solvent was eliminated at 70°C, forming a yellow gel without any segregation. The gel was calcined at 300°C for 3h, and the (Na-Nb-MA) heated material was calcined in the range of temperatures from 400 to 900°C, from 5min to 8h. Pure NaNbO3 (NN), free from amorphous carbon, which crystallized at temperatures higher than 450°C, was confirmed by a combined analysis using X-ray diffraction and UV-Raman spectroscopy. A correlation between the presence of residual carbon and the crystallite size, which was calculated using the Scherrer formula, was observed and qualitatively used to infer about this presence of residual carbon.

    Original languageEnglish
    Pages (from-to)2235-2239
    Number of pages5
    JournalCeramics International
    Issue number8
    Publication statusPublished - 2004


    • A. Powders: chemical preparation
    • B. Grain size
    • B. X-ray methods
    • D. Niobates

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Ceramics and Composites
    • Process Chemistry and Technology
    • Surfaces, Coatings and Films
    • Materials Chemistry


    Dive into the research topics of 'Qualitative measurement of residual carbon in wet-chemically synthesized powders'. Together they form a unique fingerprint.

    Cite this