Sparks, Taylor D, Gurlo, Aleksander, Bekheet, Maged F, Gaultois, Michael W 
ORCID: 0000-0003-2172-2507, Cherkashinin, Gennady, Laversenne, Laetitia and Clarke, David R
(2019)
High-temperature structure of Co<sub>3</sub>O<sub>4</sub>: Understanding spinel inversion using <i>in situ</i> and <i>ex situ</i> measurements.
PHYSICAL REVIEW B, 99 (10).
104104-.
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Abstract
In this paper we investigate the high-temperature structure of Co3O4, a compound that has been studied extensively over the last 60 years due to its unresolved high-temperature structure. In situ thermal analysis and x-ray diffraction confirm previously reported high-temperature structural changes and show that these changes are unrelated to the high-temperature decomposition to CoO. Raman-active peaks are also extinguished over the same temperature range. By considering the changing lattice parameter, A-O, and B-O bond lengths as well as cation size we are able to calculate the degree of inversion which reaches a maximum of 0.6. To further study the structure in this experimentally inaccessible range we quench samples and perform ex situ measurements including redox titration, x-ray photoelectron spectroscopy, and neutron diffraction. We do not observe any evidence of large oxygen vacancy concentrations or octahedral CoB3+ ions with high spin state. However, we do show an evolution in the magnetic moment from magnetic structure refinement from (2.4μB) to (2.7μB) that coincides exactly with the high-temperature anomaly and suggests partial inversion (0.46) of the spinel structure in fairly good agreement with the inversion calculated from bond lengths.
| Item Type: | Article |
|---|---|
| Depositing User: | Symplectic Admin |
| Date Deposited: | 30 Jan 2020 15:23 |
| Last Modified: | 15 Mar 2024 14:45 |
| DOI: | 10.1103/PhysRevB.99.104104 |
| Related URLs: | |
| URI: | https://livrepository.liverpool.ac.uk/id/eprint/3072717 |
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