Article contents
CBED Study of Mn3+ Orbital Ordering in LaMnO3
Published online by Cambridge University Press: 02 July 2020
Extract
Mn oxides of pervoskite-related structure containing Mn ions have attracted considerable interest due to the colossal magnetoresistence (CMR) effect. Doping the family of compounds La1-x Cax MnO3 with divalent Ca ion oxidizes Mn+3 to Mn4+, introducing holes in the 3d bond orbital that give rise to a series of interesting physical properties. The parent compound LaMnO3 (Pbnm) with unit cell of a=5.5367Å b=5.7473Å and c=7.6929Å, is an antiferromagnetic insulator in which orbital ordering is established due to the cooperative Jahn-Teller (JT) effect breaking the degeneracy of the electronic configuration of Mn3+ (t2g3eg1). This particular C-type orbital ordering is responsible for the A-type magnetic structure observed by Wollen and Kohler. Theoretical Monte-Carlo simulation has shown that the A-type antiferromagnetic state is stable in a model based on JT phonons, using coupling values physically reasonable for LaMnO3 and considering the small but important effect of octahedral tilting.
- Type
- Sir John Meurig Thomas Symposium: Microscopy and Microanalysis in the Chemical Sciences
- Information
- Microscopy and Microanalysis , Volume 6 , Issue S2: Proceedings: Microscopy & Microanalysis 2000, Microscopy Society of America 58th Annual Meeting, Microbeam Analysis Society 34th Annual Meeting, Microscopical Society of Canada/Societe de Microscopie de Canada 27th Annual Meeting, Philadelphia, Pennsylvania August 13-17, 2000 , August 2000 , pp. 46 - 47
- Copyright
- Copyright © Microscopy Society of America
References
- 1
- Cited by