de Godoy, MPF, Gratens, X, Chitta, VA, Mesquita, A, de Lima, MM, Cantarero, A, Rahman, G, Morbec, JM ORCID: https://orcid.org/0000-0002-1672-3575 and de Carvalho, HB (2021) Defect induced room temperature ferromagnetism in high quality Co-doped ZnO bulk samples. Journal of Alloys and Compounds, 859. 157772 - 157772.

[img] Text
Defect induced room temperature ferromagnetism.pdf - Accepted Version
Restricted to Repository staff only until 3 November 2022.
Available under License Creative Commons Attribution Non-commercial No Derivatives.

Download (10MB)

Abstract

The nature of the often reported room temperature ferromagnetism in transition metal doped oxides is still a matter of huge debate. Herein we report on room temperature ferromagnetism in high quality Co-doped ZnO (Zn1−xCoxO) bulk samples synthesized via standard solid-state reaction route. Reference paramagnetic Co-doped ZnO samples with low level of structural defects are subjected to heat treatments in a reductive atmosphere in order to introduce defects in the samples in a controlled way. A detailed structural analysis is carried out in order to characterize the induced defects and their concentration. The magnetometry revealed the coexistence of a paramagnetic and a ferromagnetic phase at room temperature in straight correlation with the structural properties. The saturation magnetization is found to increase with the intensification of the heat treatment, and, therefore, with the increase of the density of induced defects. The magnetic behavior is fully explained in terms of the bound magnetic polaron model. Based on the experimental findings, supported by theoretical calculations, we attribute the origin of the observed defect-induced-ferromagnetism to the ferromagnetic coupling between the Co ions mediated by magnetic polarons due to zinc interstitial defects.

Item Type: Article
Additional Information: The final version of this accepted article and all relevant information regarding copyrights and more, can be found online at; https://www.sciencedirect.com/science/article/pii/S0925838820341360
Uncontrolled Keywords: Doped oxides; Defect engineering; Ferromagnetism; Spintronics
Subjects: Q Science > Q Science (General)
Q Science > QD Chemistry
Q Science > QD Chemistry > QD415 Biochemistry
Divisions: Faculty of Natural Sciences > School of Chemical and Physical Sciences
Depositing User: Symplectic
Date Deposited: 02 Dec 2020 15:19
Last Modified: 05 Mar 2021 15:53
URI: https://eprints.keele.ac.uk/id/eprint/8943

Actions (login required)

View Item View Item