10 research outputs found
Electric field-assisted pressureless sintering gadolinium-, yttrium- and samarium-doped barium cerate
Electric Field-Assisted Pressureless Sintering of Ceramic Protonic Conductors
Submitted by Marco Antonio Oliveira da Silva ([email protected]) on 2018-02-22T14:44:12Z
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24398.pdf: 651304 bytes, checksum: a8955f43950e0d010b9d9633075efd15 (MD5)Made available in DSpace on 2018-02-22T14:44:12Z (GMT). No. of bitstreams: 1
24398.pdf: 651304 bytes, checksum: a8955f43950e0d010b9d9633075efd15 (MD5)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Gadolinium, yttrium and samarium-doped barium cerate pressed
pellets were submitted to flash sintering experiments isothermally
in the temperature range 800-1300oC under 200 V cm-1 electric
field. The pellets were positioned inside a dilatometer furnace with
Pt-Ir electrodes connected either to a power supply or to an
impedance analyzer to evaluate the bulk and the grain boundary
contributions to the electrical resistivity. Near full density was
achieved in the sintered samples. The combined results of
dilatometry and impedance measurements in conventionally and
flash sintered specimens show substantial improvement of the
electrical conductivity. Joule heating is assumed to be the primary
effect for sintering. Improved grain-to-grain contact and the
removal of depleted chemical species due to Joule heating at the
space charge region are proposed, respectively, as the reasons for
the decrease of the grain boundary component in the impedance
diagrams and the improvement of the bulk electrical conductivity.FAPESP: 13/07296-2CNPq: 470952/2013-0; 303483/2013-
Synthesis Of In2o3nanoparticles By Thermal Decomposition Of A Citrate Gel Precursor
This paper describes the synthesis of indium oxide by a modified sol-gel method, and the study of thermal decomposition of the metal complex in air. The characterization of the intermediate as well as the final compounds was carried out by thermogravimetry, differential thermal analysis, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and small angle X-ray scattering. The results show that the indium complex decomposes to In2O3 with the formation of an intermediate compound. Nanoparticles of cubic In2O3 with crystallite sizes in the nanosize range were formed after calcination at temperatures up to 900°C. Calcined materials are characterized by a polydisperse distribution of spherical particles with sharp and smooth surfaces. © Springer 2005.72-3203208Avivi, S., Mastai, Y., Gedanken, A., (2000) Chem. Mater., 12, p. 1229Gopchandran, K.G., Joseph, B., Abraham, J.T., Koshy, P., Vaidyan, V.K., (1997) Vacuum, 86, p. 547Granqvist, C.G., (1993) Appl. Phys. A: Solid Surf., 57, p. 19Guinier, A., Fournet, G., (1955) Small Angle Scattering of X-rays, , Wiley, New YorkGurlo, A., Barsan, N., Weimar, U., Ivanovskaya, M., Taurino, A., Siciliano, P., (2003) Chem. Mater., 15, p. 4377Gurlo, A., Ivanovskaya, M., Barsan, N., Scweizer-Berberich, M., Weimar, U., Göpel, W., Diéguez, A., (1997) Sens. Actuat. B, 44, p. 327Hamada, S., Kudo, Y., Kobayashi, T., (1993) Coll. Surf., A79, p. 227Hattori, T., Nishiyama, S., Kishi, Y., Iwadate, Y., (1993) J. Mater. Sci. Lett., 12, p. 883Hiroyuki, Y., Jun, T., Koji, M., Miura, N., Nobaru, Y., (1997) J. Electrochem. Soc., 144, pp. L158Kakihana, M., (1996) J. Sol-gel Sci. Technol., 6, p. 7Keller, R.J., (1986) The Sigma Library of FTIR Spectra, 2. , Sigma Chemical, St. LouisMarcilly, C., Courty, P., Delmon, B., (1970) J. Am. Ceram. Soc., 53, p. 56Matsumoto, T., Suzuki, J., Ohnuma, M., Kanemitsu, Y., Matsumoto, Y., (2001) Phys. Rev. B, 63, p. 195322Murali, A., Barve, A., Leppert, V.J., Risbud, S.H., Kennedy, I.M., Lee, H.W.H., (2001) Nano Lett., 1, p. 287Nyquist, R.A., Kagel, R.O., (1971) Infrared Spectra of Inorganic Compounds, 4. , Academic Press, New YorkPerez-Maquela, L.A., Wang, L., Matijevic, E., (1998) Langmuir, 14, p. 4397Semenyuk, V., Svergun, D.I., GNOM - A program package for small angle scattering data processing (1991) J. Appl. Cryst., 24, p. 537Srivastava, A., Singhi, P., Gunjikar, V.G., Sinha, A.P.B., (1985) Thermochim. Acta, 86, p. 77Steffes, H., Imawan, C., Sozbacher, F., Obermeier, E., (2001) Sens. Actuat. B, 78, p. 106Szymanski, H.A., (1966) Interpreted Infrared Spectra, 2. , Plenum Press, New YorkTadashi, T., Kengo, S., Masanori, N., (1993) Sens. Actuat. B, 13-14, p. 404Taguchi, H., Matsu-Ura, S., Nagao, M., (1997) J. Solid State Chem., 129, p. 60Tahar, R.B.H., Ban, T., Ohya, Y., Takahashi, Y., (1997) J. Appl. Phys., 82, p. 865Tanaka, S., Esaka, T., (2001) J. Mater. Res., 16, p. 1389Warren, B.E., (1990) X-ray Diffraction, p. 258. , Dover, New YorkYang, H., Tang, A., Zhang, X., Yang, W., Qiu, G., (2004) Scripta Mater., 50, p. 413Yura, K., Fredrikson, K.C., Matijevic, E., (1990) Coll. Surf., 50, p. 281Zhan, Z., Song, W., Jiang, D., (2004) J. Coll. Interface Sci., 271, p. 36