Siqueira, Kisla Prislen FélixDias, Anderson2017-05-222017-05-222011SIQUEIRA, K. P. F.; DIAS, A. Incipient crystallization of transition-metal tungstates under microwaves probed by Raman scattering and transmission electron microscopy. Journal of Nanoparticle Research, v. 13, p. 5927-5933, 2011. Disponível em: <https://link.springer.com/article/10.1007/s11051-011-0248-8>. Acesso em: 20 abr. 2017.1572-896Xhttp://www.repositorio.ufop.br/handle/123456789/7770Microwave synthesis was used to produce nanosized transition-metal tungstates in environmentally friendly conditions not yet reported by the literature: 110 and 150 C, for times of 10 and 20 min. X-ray diffraction evidenced incipient crystallized materials, while transmission electron microscopy indicates nanostructured regions of about 2–5 nm inside an amorphous matrix. Raman spectroscopy was used to probe short-range ordering in the achieved samples and also to obtain a reliable set of spectra containing all the Raman-active bands predicted by group-theory calculations. The vibrational spectra showed no extra feature, indicating that the microwave processing was able to produce short-range ordered materials without tetrahedral distortions. These distortions are frequently reported when commercially modified kitchen microwave units are employed. In this work, the syntheses were conducted in a commercial apparatus especially designed for fully controlled temperature–time–pressure conditions.en-USrestritoMicrowaveHydrothermalTungstatesMultiferroicArtigo publicado em periodicohttps://link.springer.com/article/10.1007/s11051-011-0248-8https://doi.org/10.1007/s11051-011-0248-8