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Resistivity dependence of magnetoresistance in Co/ZnO films

We report the dependence of magnetoresistance effect on resistivity (ρ) in Co/ZnO films deposited by magnetron sputtering at different sputtering pressures with different ZnO contents. The magnitude of the resistivity reflects different carrier transport regimes ranging from metallic to hopping beha...

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Autores principales: Quan, Zhi-Yong, Zhang, Li, Liu, Wei, Zeng, Hao, Xu, Xiao-Hong
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3895669/
https://www.ncbi.nlm.nih.gov/pubmed/24393445
http://dx.doi.org/10.1186/1556-276X-9-6
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author Quan, Zhi-Yong
Zhang, Li
Liu, Wei
Zeng, Hao
Xu, Xiao-Hong
author_facet Quan, Zhi-Yong
Zhang, Li
Liu, Wei
Zeng, Hao
Xu, Xiao-Hong
author_sort Quan, Zhi-Yong
collection PubMed
description We report the dependence of magnetoresistance effect on resistivity (ρ) in Co/ZnO films deposited by magnetron sputtering at different sputtering pressures with different ZnO contents. The magnitude of the resistivity reflects different carrier transport regimes ranging from metallic to hopping behaviors. Large room-temperature magnetoresistance greater than 8% is obtained in the resistivity range from 0.08 to 0.5 Ω · cm. The magnetoresistance value decreases markedly when the resistivity of the films is less than 0.08 Ω · cm or greater than 0.5 Ω · cm. When 0.08 Ω · cm < ρ < 0.5 Ω · cm, the conduction contains two channels: the spin-dependent tunneling channel and the spin-independent second-order hopping (N = 2). The former gives rise to a high room-temperature magnetoresistance effect. When ρ > 0.5 Ω · cm, the spin-independent higher-order hopping (N > 2) comes into play and decreases the tunneling magnetoresistance value. For the samples with ρ < 0.08 Ω · cm, reduced magnetoresistance is mainly ascribed to the formation of percolation paths through interconnected elongated metallic Co particles. This observation is significant for the improvement of room-temperature magnetoresistance value for future spintronic devices.
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spelling pubmed-38956692014-01-24 Resistivity dependence of magnetoresistance in Co/ZnO films Quan, Zhi-Yong Zhang, Li Liu, Wei Zeng, Hao Xu, Xiao-Hong Nanoscale Res Lett Nano Express We report the dependence of magnetoresistance effect on resistivity (ρ) in Co/ZnO films deposited by magnetron sputtering at different sputtering pressures with different ZnO contents. The magnitude of the resistivity reflects different carrier transport regimes ranging from metallic to hopping behaviors. Large room-temperature magnetoresistance greater than 8% is obtained in the resistivity range from 0.08 to 0.5 Ω · cm. The magnetoresistance value decreases markedly when the resistivity of the films is less than 0.08 Ω · cm or greater than 0.5 Ω · cm. When 0.08 Ω · cm < ρ < 0.5 Ω · cm, the conduction contains two channels: the spin-dependent tunneling channel and the spin-independent second-order hopping (N = 2). The former gives rise to a high room-temperature magnetoresistance effect. When ρ > 0.5 Ω · cm, the spin-independent higher-order hopping (N > 2) comes into play and decreases the tunneling magnetoresistance value. For the samples with ρ < 0.08 Ω · cm, reduced magnetoresistance is mainly ascribed to the formation of percolation paths through interconnected elongated metallic Co particles. This observation is significant for the improvement of room-temperature magnetoresistance value for future spintronic devices. Springer 2014-01-06 /pmc/articles/PMC3895669/ /pubmed/24393445 http://dx.doi.org/10.1186/1556-276X-9-6 Text en Copyright © 2014 Quan et al.; licensee Springer. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Nano Express
Quan, Zhi-Yong
Zhang, Li
Liu, Wei
Zeng, Hao
Xu, Xiao-Hong
Resistivity dependence of magnetoresistance in Co/ZnO films
title Resistivity dependence of magnetoresistance in Co/ZnO films
title_full Resistivity dependence of magnetoresistance in Co/ZnO films
title_fullStr Resistivity dependence of magnetoresistance in Co/ZnO films
title_full_unstemmed Resistivity dependence of magnetoresistance in Co/ZnO films
title_short Resistivity dependence of magnetoresistance in Co/ZnO films
title_sort resistivity dependence of magnetoresistance in co/zno films
topic Nano Express
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3895669/
https://www.ncbi.nlm.nih.gov/pubmed/24393445
http://dx.doi.org/10.1186/1556-276X-9-6
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