The role of defects in microwave and conventionally synthesized LaCoO3 perovskite

Prado-Gonjal, J.; Gutiérrez-Seijas, J.; Herrero Ansorregui, I.; Morán, E.; Terry, I.; Schmidt, R.

doi:10.1016/j.jeurceramsoc.2015.12.014

The role of defects in microwave and conventionally synthesized LaCoO3 perovskite

Prado-Gonjal, J.; Gutiérrez-Seijas, J.; Herrero Ansorregui, I.; Morán, E.; Terry, I.; Schmidt, R.

Authors

J. Prado-Gonjal

J. Gutiérrez-Seijas

I. Herrero Ansorregui

E. Morán

Dr Ian Terry ian.terry@durham.ac.uk
Associate Professor

R. Schmidt

Abstract

In this work we investigate the magnetic, dielectric and charge transport properties of LaCoO3 (LCO) synthesized by two different techniques: microwave assisted and conventionally heated ceramic synthesis. The rapid microwave synthesis conditions are far away from thermodynamic equilibrium and are found to lead to modified crystal defect properties as compared to conventional synthesis. The thermally induced magnetic spin state transition at Ts1 ≈ 80 K is exemplified by temperature (T)-dependent dielectric spectroscopy data, which reveal the appearance of an additional dielectric contribution that is correlated to the transition. Magnetisation, M vs T, and electrical resistivity, ρ vs T, curves show that the additional dielectric phase is strongly influenced by magnetic defects and may be associated with higher spin state clusters in a magnetic spin-state coexistence scenario. We suggest that defects such as oxygen vacancies act as magnetic nucleation centres across the spin state transition Ts1 for the formation of higher spin state clusters in LCO perovskites.

Citation

Prado-Gonjal, J., Gutiérrez-Seijas, J., Herrero Ansorregui, I., Morán, E., Terry, I., & Schmidt, R. (2016). The role of defects in microwave and conventionally synthesized LaCoO3 perovskite. Journal of the European Ceramic Society, 36(5), 1197-1206. https://doi.org/10.1016/j.jeurceramsoc.2015.12.014

Journal Article Type	Article
Acceptance Date	Dec 12, 2015
Online Publication Date	Dec 23, 2015
Publication Date	Apr 1, 2016
Deposit Date	Jan 18, 2016
Publicly Available Date	Dec 12, 2016
Journal	Journal of the European Ceramic Society
Print ISSN	0955-2219
Publisher	Elsevier
Peer Reviewed	Peer Reviewed
Volume	36
Issue	5
Pages	1197-1206
DOI	https://doi.org/10.1016/j.jeurceramsoc.2015.12.014
Keywords	Cobaltite, Microwave synthesis, Magnetic defects, Impedance spectroscopy.

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© 2015 This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/