2023-Sustainable Industrial Processing Summit
SIPS2023 Volume 8. 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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UNUSUAL CHARGE DISTRIBUTION AND PHYSICAL PROPERTIES INDUCED BY Bi,Pb 6S ELECTRONS
Takumi Nishikubo1; Yuki Sakai1; Masaki Azuma2;1KANAGAWA INSTITUTE OF INDUSTRIAL SCIENCE AND TECHNOLOGY, Ebina, Japan; 2TOKYO INST. OF TECHNOLOGY, Yokohama, Japan;
Type of Paper: Regular
Id Paper: 150
Topic: 52
Abstract:
Bi and Pb have a unique 6s0 and 6s2 electron configuration that creates charge degrees of freedom. Due to the lack of this 6s1 electron configuration, a property called valence skipper, Bi takes 3+ and 5+ and Pb takes 2+ and 4+. In particular, for perovskite compounds containing Bi or Pb at the A site, the valence state changes according to the depth of the d-orbitals of the transition metal ions corresponding to the order in the periodic table of the elements due to the close relationship between the 6s level of Pb or Bi and the 3d level of the 3d transition metal ions. For BiMO3, M= Cr, Mn, Fe, Co, the state is Bi3+M3+O3, while BiNiO3 has a specific valence state of Bi3+0.5Bi5+0.5Ni2+O3. PbMO3 has Pb2+0.5Pb4+0.5MO3 for M= Ti and V, Pb2+0.5Pb4+0.5M3+O3 for M= Cr and Fe, PbCoO3 has Pb2+0.25Pb4+0.75Co2+0.5Co3+0.5O3, PbNiO3 has Pb4+Ni2+O3. In BiNiO3 and PbMO3 (M = Cr, Fe and Co), Bi and Pb become charge disproportionated in the 6s0 and 6s2 states, and temperature- and pressure-induced elimination of charge disproportionation and charge transfer phase transitions occur. These charge transfer phase transition causes leads to unique physical properties such as negative thermal expansion.