2023-Sustainable Industrial Processing Summit
Poeppelmeier Intl. Symp. / Solid State Chemistry
| Editors: | F. Kongoli, M. Delferro, P. S. Halasyamani, M. A. Alario-Franco, F. Marquis, A. Tressaud, H. Kageyama |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2023 |
| Pages: | 144 pages |
| ISBN: | 978-1-989820-86-5 (CD) |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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THE COMPLEX STRUCTURE & MICROSTRUCTURE OF “CUBIC” PbCrO3
Miguel A. Alario Franco1;1COMPLUTENSE U. OF MADRID, Madrid, Spain;
Type of Paper: Regular
Id Paper: 95
Topic: 52
Abstract:
PbCrO3 perovskite was first synthesized by Roth and deVries in the late 1960s [1]. Chamberland and Moeller [2] also synthesized PbCrO3 and their structural results were in agreement with the previous ones but, in addition, reported an unusual broadening of the diffraction peaks even using monochromatic CuKa1 radiation. These broad lines in the X-ray powder patterns were also observed for the same compound by Goodenough et al. [3]. However, in these works neither atomic concentration nor microstructural studies were considered and/or analyzed. A rather puzzling situation concerning the 3d-metal, (4+) lead-based perovskites, resides in the fact that while PbTiO3 is tetragonal with c/a 1⁄4 1.064 and ferroelectric with Tc<>763 K [4], and PbVO3 is also tetragonal with a higher tetragonality factor, c/a 1⁄4 1.229 [3,4], PbCrO3 has been described as cubic. This is unexpected as in terms of ionic size the following trend is observed: VIr4+Cr< VIr4+V< VIr4+Ti, (0.55, 0.58, and 0.605 A, respectively [4]). Thus, one could expect that PbCrO3 should be even more tetragonal since the Cr(IV)–O bond would be more covalent. We have performed a structural and microstructural study using XRD, selected area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM) to elucidate the origin of the abnormal broadening of the XRD maxima and to clarify the origin of the cubic structure of PbCrO3. In this way, it is shown that the lead-perovskite compound ‘‘PbCrO3’’ has a Pb deficiency, resulting in a modulated structure within a complex microdomain texture.
Keywords:
Advanced Characterization Techniques and Applications; Advances in the synthesis routes;References:
[1] W.L. Roth, R.C. DeVries, J. Appl. Phys. 38 (1967) 951.[2] B.L. Chamberland, C.W. Moeller, J. Solid State Chem. 5 (1972) 39.
[3] R.V. Sphanchenko, V.V. Chernaya, A.A. Tsirlin, P.V. Chizhov,, D.E. Sklovsky, E.V. Antipov, Chem. Mater. 16 (2004) 3267.
[4] A.A. Belik, M. Azuma, T. Saito, Y. Shimakawa, M. Takano, Chem. Mater. 17 (2005) 269.