Abstract
The magnetic behavior of -Fe/Au nanoparticle (NP) assemblies is studied over a very wide range of dipolar interactions among -Fe NPs, by changing the volume density of the -Fe NP. The assembly whose -Fe NP density is lower than 0.1% exhibits typical superparamagnetic behavior. When Fe NP density exceeds 8.6% the magnetic dynamics changes to that resembling superspin glass. Moreover, NP assembly with highest Fe concentration (43%), whose dipolar interaction is enormously strong compared with previous studies, exhibits a two-stage magnetic transition, i.e., ferromagnetic and spin glass-like transitions at 385 K and around 150 K, respectively. Therefore, we first observed the reentrant spin glass-like magnetism at the limit of strong interaction in a close-packed NP assembly. Based on these observations, the magnetic phase diagram of the interacting -Fe NP assembly is determined over a very wide range of interaction.
| Original language | English |
|---|---|
| Article number | 176001 |
| Journal | Journal of Physics Condensed Matter |
| Volume | 26 |
| Issue number | 17 |
| DOIs | |
| Publication status | Published - 2014 Apr 30 |
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Keywords
- dipolar interaction
- nanoparticle assembly
- superferromagnetism
- superspin glass
ASJC Scopus subject areas
- Condensed Matter Physics
- Materials Science(all)
- Medicine(all)
Cite this
Magnetic ordered states induced by interparticle magnetostatic interaction in -Fe/Au mixed nanoparticle assembly. / Hiroi, Kosuke; Kura, Hiroaki; Ogawa, Tomoyuki; Takahashi, Migaku; Sato, Tetsuya.
In: Journal of Physics Condensed Matter, Vol. 26, No. 17, 176001, 30.04.2014.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Magnetic ordered states induced by interparticle magnetostatic interaction in -Fe/Au mixed nanoparticle assembly
AU - Hiroi, Kosuke
AU - Kura, Hiroaki
AU - Ogawa, Tomoyuki
AU - Takahashi, Migaku
AU - Sato, Tetsuya
PY - 2014/4/30
Y1 - 2014/4/30
N2 - The magnetic behavior of -Fe/Au nanoparticle (NP) assemblies is studied over a very wide range of dipolar interactions among -Fe NPs, by changing the volume density of the -Fe NP. The assembly whose -Fe NP density is lower than 0.1% exhibits typical superparamagnetic behavior. When Fe NP density exceeds 8.6% the magnetic dynamics changes to that resembling superspin glass. Moreover, NP assembly with highest Fe concentration (43%), whose dipolar interaction is enormously strong compared with previous studies, exhibits a two-stage magnetic transition, i.e., ferromagnetic and spin glass-like transitions at 385 K and around 150 K, respectively. Therefore, we first observed the reentrant spin glass-like magnetism at the limit of strong interaction in a close-packed NP assembly. Based on these observations, the magnetic phase diagram of the interacting -Fe NP assembly is determined over a very wide range of interaction.
AB - The magnetic behavior of -Fe/Au nanoparticle (NP) assemblies is studied over a very wide range of dipolar interactions among -Fe NPs, by changing the volume density of the -Fe NP. The assembly whose -Fe NP density is lower than 0.1% exhibits typical superparamagnetic behavior. When Fe NP density exceeds 8.6% the magnetic dynamics changes to that resembling superspin glass. Moreover, NP assembly with highest Fe concentration (43%), whose dipolar interaction is enormously strong compared with previous studies, exhibits a two-stage magnetic transition, i.e., ferromagnetic and spin glass-like transitions at 385 K and around 150 K, respectively. Therefore, we first observed the reentrant spin glass-like magnetism at the limit of strong interaction in a close-packed NP assembly. Based on these observations, the magnetic phase diagram of the interacting -Fe NP assembly is determined over a very wide range of interaction.
KW - dipolar interaction
KW - nanoparticle assembly
KW - superferromagnetism
KW - superspin glass
UR - http://www.scopus.com/inward/record.url?scp=84903363990&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84903363990&partnerID=8YFLogxK
U2 - 10.1088/0953-8984/26/17/176001
DO - 10.1088/0953-8984/26/17/176001
M3 - Article
VL - 26
JO - Journal of Physics Condensed Matter
JF - Journal of Physics Condensed Matter
SN - 0953-8984
IS - 17
M1 - 176001
ER -