Abstract
HREM and XPD methods are used to study the microstructure of La1 − x Ca x MnO3 perovskite-like oxides synthesized by pyrolysis of polymer-salt compositions. The XPD data show that the samples studied are single-phase solid solutions. Morphological transitions are observed in series of samples depending on the substitution parameter x. At 0 ≤ x ≤ 0.4 the samples can be characterized by rhombic symmetry (space group Pnmb); at 0.5 ≤ x ≤ 0.8 the symmetry increases to the tetragonal space group I4/mmm; at 0.9 ≤ x ≤ 1 the symmetry lowers to the monoclinic space group P1121. Heating of samples with x = 0.5 and 0.8 up to 1200°C in air does not lead to noticeable changes in the sample structure, which indicates their high thermal stability. When the La0.2Ca0.8MnO3 sample is heated to 1100°C in vacuum nanocrystalline states with particle disintegration into microphases of different structures form because of a partial decomposition of the solid solution. As a result, a system of Mn3O4 nanoparticles appears, which is coherently bound with the perovskite phase of a defective structure.
Similar content being viewed by others
References
Yu. A. Izyumov and Yu. N. Skryabin, Usp. Fiz. Nauk 171, 121 (2001) [Phys. Usp. 44, 109 (2001)].
P. R. Sagdeo, S. Anwar, and N. P. Lalla, Powder Diffraction, No. 21 (1), 40 (2006).
L. A. Isupova, S. V. Tsybulya, G. N. Kryukova, et al., Solid State Ion. 141–142, 417 (2001).
P. Majewski, L. Epple, M. Rozumek, H. Schluckwerderet, et al., J. Mater. Res. 5, 1161 (2000).
M. P. Pechini, “Method of Preparing Lead and Alkaline Earth Titanates and Niobates and Coating Method Using the Same to Form a Capacitor,” US Patent No. 3.330.697 (1967).
A. G. Rudskaya, M. F. Kupriyanov, N. B. Kofanova, et al., http://zhurnal.ape.relarn.ru/articles/2004/037.html.
O. I. Lebedev, G. Van Tendeloo, S. Amelinckx, et al., Phys. Rev. B 58(12), 8065 (1998).
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © E.Yu. Gerasimov, V.I. Zaikovskii, S.V. Tsybulya, L.A. Isupova, 2009, published in Poverkhnost’. Rentgenovskie, Sinkhrotronnye i Neitronnye Issledovaniya, No. 10, pp. 10–15.
Rights and permissions
About this article
Cite this article
Gerasimov, E.Y., Zaikovskii, V.I., Tsybulya, S.V. et al. A study of the microstructure of La1 − x Ca x MnO3 (x = 0.5, 0.8) solid solutions. J. Surf. Investig. 3, 756–760 (2009). https://doi.org/10.1134/S1027451009050164
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S1027451009050164