Room temperature ferromagnetism of ZnO nanocrystals in amorphous ZnO- Al2 O3 matrix

Y. W. Ma; J. Ding; D. C. Qi; J. B. Yi; H. M. Fan; H. Gong; A. T.S. Wee; A. Rusydi

doi:10.1063/1.3206654

Room temperature ferromagnetism of ZnO nanocrystals in amorphous ZnO- Al₂ O₃ matrix

Y. W. Ma, J. Ding^*, D. C. Qi, J. B. Yi, H. M. Fan, H. Gong, A. T.S. Wee, A. Rusydi

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

24 Scopus citations

Abstract

In this work, we demonstrate room temperature ferromagnetism of ZnO nanocrystals (NCs) embedded in alumina-based amorphous matrix. Our study has shown that solid solution occurred for lower Al concentration [≥x=0.09 for (Zn_1-x, Al_x) O]. No ferromagnetism appears in Al-doped ZnO with x≥0.09. With higher Al concentration, alumina-based amorphous structure appeared and fully amorphous was found in the composition of (Zn _0.30, Al_0.70) O. Ferromagnetism was found in (Zn _1-x, Al_x) O with a threshold of 16 mol % of Al. The room temperature ferromagnetism was found to be attributed to ZnO NCs in an alumina-based amorphous ZnO- Al₂ O₃ matrix. Ferromagnetism reached a maximum with a volume percentage of ZnO NCs to be ∼27 vol %. The detailed investigations (transmission electron microscopy, x-ray photoelectron spectroscopy, and superconducting quantum interference device) show that the optimized size of these NCs is in the range of 4-5 nm. No ferromagnetism appears if the sample contains a fully amorphous structure.

Original language	English
Article number	072501
Journal	Applied Physics Letters
Volume	95
Issue number	7
DOIs	https://doi.org/10.1063/1.3206654
State	Published - 2009
Externally published	Yes

ASJC Scopus subject areas

Physics and Astronomy (miscellaneous)

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10.1063/1.3206654

Cite this

@article{4d7151a9b57846628eb4f9fe878afc87,

title = "Room temperature ferromagnetism of ZnO nanocrystals in amorphous ZnO- Al2 O3 matrix",

abstract = "In this work, we demonstrate room temperature ferromagnetism of ZnO nanocrystals (NCs) embedded in alumina-based amorphous matrix. Our study has shown that solid solution occurred for lower Al concentration [≥x=0.09 for (Zn1-x, Alx) O]. No ferromagnetism appears in Al-doped ZnO with x≥0.09. With higher Al concentration, alumina-based amorphous structure appeared and fully amorphous was found in the composition of (Zn 0.30, Al0.70) O. Ferromagnetism was found in (Zn 1-x, Alx) O with a threshold of 16 mol % of Al. The room temperature ferromagnetism was found to be attributed to ZnO NCs in an alumina-based amorphous ZnO- Al2 O3 matrix. Ferromagnetism reached a maximum with a volume percentage of ZnO NCs to be ∼27 vol %. The detailed investigations (transmission electron microscopy, x-ray photoelectron spectroscopy, and superconducting quantum interference device) show that the optimized size of these NCs is in the range of 4-5 nm. No ferromagnetism appears if the sample contains a fully amorphous structure.",

author = "Ma, {Y. W.} and J. Ding and Qi, {D. C.} and Yi, {J. B.} and Fan, {H. M.} and H. Gong and Wee, {A. T.S.} and A. Rusydi",

year = "2009",

doi = "10.1063/1.3206654",

language = "English",

volume = "95",

journal = "Applied Physics Letters",

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AU - Ma, Y. W.

AU - Ding, J.

AU - Qi, D. C.

AU - Yi, J. B.

AU - Fan, H. M.

AU - Gong, H.

AU - Wee, A. T.S.

AU - Rusydi, A.

PY - 2009

Y1 - 2009

N2 - In this work, we demonstrate room temperature ferromagnetism of ZnO nanocrystals (NCs) embedded in alumina-based amorphous matrix. Our study has shown that solid solution occurred for lower Al concentration [≥x=0.09 for (Zn1-x, Alx) O]. No ferromagnetism appears in Al-doped ZnO with x≥0.09. With higher Al concentration, alumina-based amorphous structure appeared and fully amorphous was found in the composition of (Zn 0.30, Al0.70) O. Ferromagnetism was found in (Zn 1-x, Alx) O with a threshold of 16 mol % of Al. The room temperature ferromagnetism was found to be attributed to ZnO NCs in an alumina-based amorphous ZnO- Al2 O3 matrix. Ferromagnetism reached a maximum with a volume percentage of ZnO NCs to be ∼27 vol %. The detailed investigations (transmission electron microscopy, x-ray photoelectron spectroscopy, and superconducting quantum interference device) show that the optimized size of these NCs is in the range of 4-5 nm. No ferromagnetism appears if the sample contains a fully amorphous structure.

AB - In this work, we demonstrate room temperature ferromagnetism of ZnO nanocrystals (NCs) embedded in alumina-based amorphous matrix. Our study has shown that solid solution occurred for lower Al concentration [≥x=0.09 for (Zn1-x, Alx) O]. No ferromagnetism appears in Al-doped ZnO with x≥0.09. With higher Al concentration, alumina-based amorphous structure appeared and fully amorphous was found in the composition of (Zn 0.30, Al0.70) O. Ferromagnetism was found in (Zn 1-x, Alx) O with a threshold of 16 mol % of Al. The room temperature ferromagnetism was found to be attributed to ZnO NCs in an alumina-based amorphous ZnO- Al2 O3 matrix. Ferromagnetism reached a maximum with a volume percentage of ZnO NCs to be ∼27 vol %. The detailed investigations (transmission electron microscopy, x-ray photoelectron spectroscopy, and superconducting quantum interference device) show that the optimized size of these NCs is in the range of 4-5 nm. No ferromagnetism appears if the sample contains a fully amorphous structure.

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