Spin Polarization and Quantum Spins in Au Nanoparticles
The present study focuses on investigating the magnetic properties and the critical particle size for developing sizable spontaneous magnetic moment of bare Au nanoparticles. Seven sets of bare Au nanoparticle assemblies, with diameters from 3.5 to 17.5 nm, were fabricated with the gas condensation...
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doaj-2781521561c94c1dbbe69a9a8e332f332020-11-24T21:40:07ZengMDPI AGInternational Journal of Molecular Sciences1422-00672013-08-01149176181764210.3390/ijms140917618Spin Polarization and Quantum Spins in Au NanoparticlesWen-Hsien LiChin-Wei WangChi-Yen LiSunil K. KarnaThe present study focuses on investigating the magnetic properties and the critical particle size for developing sizable spontaneous magnetic moment of bare Au nanoparticles. Seven sets of bare Au nanoparticle assemblies, with diameters from 3.5 to 17.5 nm, were fabricated with the gas condensation method. Line profiles of the X-ray diffraction peaks were used to determine the mean particle diameters and size distributions of the nanoparticle assemblies. The magnetization curves M(Ha) reveal Langevin field profiles. Magnetic hysteresis was clearly revealed in the low field regime even at 300 K. Contributions to the magnetization from different size particles in the nanoparticle assemblies were considered when analyzing the M(Ha) curves. The results show that the maximum particle moment will appear in 2.4 nm Au particles. A similar result of the maximum saturation magnetization appearing in 2.3 nm Au particles is also concluded through analysis of the dependency of the saturation magnetization MP on particle size. The MP(d) curve departs significantly from the 1/d dependence, but can be described by a log-normal function. Magnetization can be barely detected for Au particles larger than 27 nm. Magnetic field induced Zeeman magnetization from the quantum confined Kubo gap opening appears in Au nanoparticles smaller than 9.5 nm in diameter.http://www.mdpi.com/1422-0067/14/9/17618Au nanoparticlespontaneous particle momentfield induced Zeeman magnetization |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Wen-Hsien Li Chin-Wei Wang Chi-Yen Li Sunil K. Karna |
spellingShingle |
Wen-Hsien Li Chin-Wei Wang Chi-Yen Li Sunil K. Karna Spin Polarization and Quantum Spins in Au Nanoparticles International Journal of Molecular Sciences Au nanoparticle spontaneous particle moment field induced Zeeman magnetization |
author_facet |
Wen-Hsien Li Chin-Wei Wang Chi-Yen Li Sunil K. Karna |
author_sort |
Wen-Hsien Li |
title |
Spin Polarization and Quantum Spins in Au Nanoparticles |
title_short |
Spin Polarization and Quantum Spins in Au Nanoparticles |
title_full |
Spin Polarization and Quantum Spins in Au Nanoparticles |
title_fullStr |
Spin Polarization and Quantum Spins in Au Nanoparticles |
title_full_unstemmed |
Spin Polarization and Quantum Spins in Au Nanoparticles |
title_sort |
spin polarization and quantum spins in au nanoparticles |
publisher |
MDPI AG |
series |
International Journal of Molecular Sciences |
issn |
1422-0067 |
publishDate |
2013-08-01 |
description |
The present study focuses on investigating the magnetic properties and the critical particle size for developing sizable spontaneous magnetic moment of bare Au nanoparticles. Seven sets of bare Au nanoparticle assemblies, with diameters from 3.5 to 17.5 nm, were fabricated with the gas condensation method. Line profiles of the X-ray diffraction peaks were used to determine the mean particle diameters and size distributions of the nanoparticle assemblies. The magnetization curves M(Ha) reveal Langevin field profiles. Magnetic hysteresis was clearly revealed in the low field regime even at 300 K. Contributions to the magnetization from different size particles in the nanoparticle assemblies were considered when analyzing the M(Ha) curves. The results show that the maximum particle moment will appear in 2.4 nm Au particles. A similar result of the maximum saturation magnetization appearing in 2.3 nm Au particles is also concluded through analysis of the dependency of the saturation magnetization MP on particle size. The MP(d) curve departs significantly from the 1/d dependence, but can be described by a log-normal function. Magnetization can be barely detected for Au particles larger than 27 nm. Magnetic field induced Zeeman magnetization from the quantum confined Kubo gap opening appears in Au nanoparticles smaller than 9.5 nm in diameter. |
topic |
Au nanoparticle spontaneous particle moment field induced Zeeman magnetization |
url |
http://www.mdpi.com/1422-0067/14/9/17618 |
work_keys_str_mv |
AT wenhsienli spinpolarizationandquantumspinsinaunanoparticles AT chinweiwang spinpolarizationandquantumspinsinaunanoparticles AT chiyenli spinpolarizationandquantumspinsinaunanoparticles AT sunilkkarna spinpolarizationandquantumspinsinaunanoparticles |
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