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Crystal structure refinement of Co-doped lanthanum chromites

Published online by Cambridge University Press:  06 March 2012

H. P. S. Corrêa
Affiliation:
Instituto de Química, Universidade Estadual Paulista (UNESP), R. Professor Degni s/n, 14800-900 Araraquara, São Paulo, Brazil
C. O. Paiva-Santos
Affiliation:
Instituto de Química, Universidade Estadual Paulista (UNESP), R. Professor Degni s/n, 14800-900 Araraquara, São Paulo, Brazil
L. F. Setz
Affiliation:
Instituto de Pesquisas Energéticas e Nucleares (IPEN), Campus Universidade de São Paulo (USP), 05508-900 São Paulo, São Paulo, Brazil
L. G. Martinez
Affiliation:
Instituto de Pesquisas Energéticas e Nucleares (IPEN), Campus Universidade de São Paulo (USP), 05508-900 São Paulo, São Paulo, Brazil
S. R. H. Mello-Castanho
Affiliation:
Instituto de Pesquisas Energéticas e Nucleares (IPEN), Campus Universidade de São Paulo (USP), 05508-900 São Paulo, São Paulo, Brazil
M. T. D. Orlando
Affiliation:
Departamento de Física e Química, Universidade Federal do Espírito Santo (UFES), Vitória, Espírito Santo, Brazil

Abstract

Results of crystal structure refinements and phase quantification for samples of Co-doped lanthanum chromites with nominal composition LaCr1−xCoxO3, for x=0.00, 0.10, 0.20, and 0.30, prepared by combustion synthesis are presented. The resulting powders were characterized by scanning electron microscopy and X-ray diffraction (XRD). The XRD patterns were obtained with Cu Kα radiation for non-doped lanthanum chromite sample and additionally with Cr Kα radiation for Co-doped lanthanum chromites samples, in order to enhance the signal from scattering. Rietveld analysis of XRD data showed that the studied samples presented the lanthanum chromite with an orthorhombic structure (Pnma), except for the composition with x=0.30, in which the space group was found to be R3c.

Type
Technical Articles
Copyright
Copyright © Cambridge University Press 2008

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References

Badwal, S.P. S. (2001). “Stability of solid oxide fuel cell components,” Solid State IonicsSSIOD3 143, 3946. ssi, SSIOD3 CrossRefGoogle Scholar
Berger, D., Jitaru, I., Stanica, N., Perego, R., and Schoonman, J. (2001). “Complex precursors for doped lanthanum chromite synthesis,” J. Mater. Synth. Process.JMSPEI 9, 137142. jsw, JMSPEI CrossRefGoogle Scholar
Denton, A.R., and Ashcroft, N.W. (1991). “Vegard’s law,” Phys. Rev. APLRAAN 43, 31613164. pra, PLRAAN CrossRefGoogle ScholarPubMed
Fergus, J.W. (2004). “Lanthanum chromite-based materials for solid oxide fuel cell interconnects,” Solid State IonicsSSIOD3 171, 115. ssi, SSIOD3 CrossRefGoogle Scholar
Finger, L.W., Cox, D.E., and Jephcoat, A.P. (1994). “A correction for powder diffraction peak asymmetry due to axial divergence,” J. Appl. Crystallogr.JACGAR 27, 892900. acr, JACGAR CrossRefGoogle Scholar
Hashimoto, T., Tsuzuki, N., Kishi, A., Takagi, K., Tsuda, K., Tanaka, M., Oikawa, K., Kamiyama, T., Yoshida, K., Tagawa, H., and Dokiya, M. (2000). “Analysis of crystal structure and phase transition of LaCrO3 by various diffraction measurements,” Solid State IonicsSSIOD3 132, 181188. ssi, SSIOD3 CrossRefGoogle Scholar
Hrovat, M., Bernik, S., Holc, J., Kolar, D., and Dacar, B. (1995). “Preliminary data on subsolidus phase equilibria in the La2O3-Cr2O3-Y2O3 and La2O3-Cr2O3-ZrO2 systems,” J. Mater. Sci. Lett.JMSLD5 14, 16841687. jml, JMSLD5 CrossRefGoogle Scholar
ICDD (2005). “Powder Diffraction File,” International Centre for Diffraction Data, edited by McClune, W. F., Newtown Square, PA, 19073-3272.Google Scholar
Khattak, C.P., and Cox, D.E. (1977). “Profile analysis of X-ray powder diffractometer data: structural refinement of La0.75Sr0.25CrO3,” J. Appl. Crystallogr.JACGAR 10, 405411. acr, JACGAR CrossRefGoogle Scholar
Larson, A.C., and Von Dreele, R.B. (2000). General Structure Analysis System (GSAS) (Report LAUR 86–748) (Los Alamos National Laboratory, Los Alamos, New Mexico).Google Scholar
Minh, N.Q. (1993). “Ceramic fuel cells,” J. Am. Ceram. Soc.JACTAW 76, 563588. jac, JACTAW CrossRefGoogle Scholar
Mori, M., Yamamoto, T., Itoh, H., and Watanabe, T. (1997). “Compatibility of alkaline earth metal (Mg, Ca, Sr)-doped lanthanum chromites as separators in planar-type high-temperature solid oxide fuel cells,” J. Mater. Sci.JMTSAS 32, 24232431. jmt, JMTSAS CrossRefGoogle Scholar
Naray-Szabo, S. (1943). “Die Strukturen von Verbindungen ABO3 Schwester Strukturen,” Naturwiss.NATWAY 31, 466467. naw, NATWAY CrossRefGoogle Scholar
NIST (2005). Certificate of Analysis, Standard Reference Material 676, Alumina Internal Standard (National Institute of Standards and Technology, Gaithersburg, Maryland) 〈https://srmors.nist.gov/view_cert.cfm?srm=676〉.Google Scholar
Oikawa, K., Kamiyama, T., Hashimoto, T., Shimojyo, Y., and Morii, Y. (2000). “Structural phase transition of orthorhombic LaCrO3 studied by neutron powder diffraction,” J. Solid State Chem.JSSCBI 154, 524529. jss, JSSCBI CrossRefGoogle Scholar
Sakai, N., Fjellvâg, H., and Hauback, B.C. (1996). “Structural, magnetic, and thermal properties of La1−tCatCrO3−δ,” J. Solid State Chem.JSSCBI 121, 202213. jss, JSSCBI CrossRefGoogle Scholar
Setz, L.F. G., Corrêa, H.P. S., Paiva-Santos, C.O., and Mello-Castanho, S.R. H. (2006). “Sintering of cobalt and strontium doped lanthanum chromite obtained by combustion synthesis,” Mater. Sci. ForumMSFOEP 530–531, 671676. msf, MSFOEP CrossRefGoogle Scholar
Shannon, R.D. (1976). “Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides,” Acta Crystallogr., Sect. A: Cryst. Phys., Diffr., Theor. Gen. Crystallogr.ACACBN 32, 751767. aca, ACACBN CrossRefGoogle Scholar
Simner, S., Hardy, J., Stevenson, J., and Armstrong, T. (1999). “Sintering mechanisms in strontium doped lanthanum chromite,” J. Mater. Sci.JMTSAS 34, 57215732. jmt, JMTSAS CrossRefGoogle Scholar
Srilomsak, S., Schilling, D., and Anderson, H. (1989). “Expansion studies on cathode and interconnect oxides,” in First International Symposium on Solid Oxide Fuel Cells, edited by Singhal, S. C. (Electrochemical Society, Pennington, New Jersey), Vol. 89–11, pp. 129–140.Google Scholar
Stephens, P.W. (1999). “Phenomenological model of anisotropic peak broadening in powder diffraction,” J. Appl. Crystallogr.JACGAR 32, 281289. acr, JACGAR CrossRefGoogle Scholar
Taguchi, H., Matsu-ura, S., Nagao, M. and Kido, H. (1999). “Electrical properties of perovskite-type La(Cr1−xMnx)O3+δ,” Physica BPHYBE3 270, 325331. phb, PHYBE3 CrossRefGoogle Scholar
Taguchi, H., Nagao, M., and Takeda, Y. (1995). “Relationship between the electrical properties and crystal structure of (La1−xNdx)CrO3 (0≤x≤1.0),” J. Solid State Chem.JSSCBI 114, 236241. jss, JSSCBI CrossRefGoogle Scholar
Tezuka, K., Hinatsu, Y., Nakamura, A., Inami, T., Shimojo, Y., and Morii, Y. (1998). “Magnetic and neutron diffraction study on perovskites La1−xSrxCrO3,” J. Solid State Chem.JSSCBI 141, 404410. jss, JSSCBI CrossRefGoogle Scholar
Thompson, P., Cox, D.E., and Hastings, J.B. (1987). “Rietveld refinement of Debye-Scherrer synchrotron X-ray data from Al2O3,” J. Appl. Crystallogr.JACGAR 20, 7983. acr, JACGAR CrossRefGoogle Scholar
Toby, B.H. (2001). “EXPGUI, a graphical user interface for GSAS,” J. Appl. Crystallogr.JACGAR 34, 210213. acr, JACGAR CrossRefGoogle Scholar
Tolochko, S.P., Kononyuk, I.F., Lyutsko, V.A., and Zonov, Y.G. (1987). “Phase transitions in solid solutions based on lanthanum chromite,” Inorg. Mater.INOMAF 23, 13421345. inm, INOMAF Google Scholar
Wold, A., and Ward, R. (1954). “Perovskite-type oxides of cobalt, chromium and vanadium with some rare earth elements,” J. Am. Chem. Soc.JACSAT 76, 10291030. acs, JACSAT CrossRefGoogle Scholar