Abstract
We measure the magnetization of fine cobalt particles by SQUID and pulsed magnetic fields up to 35 T. These measurements have been made on two samples (C1, C2) with nonagglomerated particles. The analysis of the magnetic meaurements evidences very narrow log-normal size distribution centered around 1.5nm (≅ 150 atoms) and 1.9 nm (≅ 310 atoms) for C1 and C2, respectively. Magnetization at 4.2 K seems to saturate in fields up to 5 T leading to an enhanced mean magnetic moment per atom compared to bulk value (1.72/μB). However, magnetization measurements up to 35 T do not permit to reach saturation, and show a continuous increase of μCo reaching 2.1 ± 0.1μB (C1) and 1.9 ± 0.1μB (C2). The effective magnetic anisotropies are found to be larger than those of bulk materials and decrease with increasing particle size. These features are associated with the large influence of the surface atoms.
| Original language | English |
|---|---|
| Pages (from-to) | 532-536 |
| Number of pages | 5 |
| Journal | Physica B: Condensed Matter |
| Volume | 246-247 |
| Publication status | Published - May 29 1998 |
| Externally published | Yes |
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Keywords
- Cobalt
- Effective magnetic anisotropy
- Fine particle
- Magnetization
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
Cite this
Magnetization measurements on fine cobalt particles. / Respaud, M.; Broto, J. M.; Rakoto, H.; Ousset, J. C.; Osuna, J.; Ould Ely, T.; Amiens, C.; Chaudret, B.; Askenazy, S.
In: Physica B: Condensed Matter, Vol. 246-247, 29.05.1998, p. 532-536.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Magnetization measurements on fine cobalt particles
AU - Respaud, M.
AU - Broto, J. M.
AU - Rakoto, H.
AU - Ousset, J. C.
AU - Osuna, J.
AU - Ould Ely, T.
AU - Amiens, C.
AU - Chaudret, B.
AU - Askenazy, S.
PY - 1998/5/29
Y1 - 1998/5/29
N2 - We measure the magnetization of fine cobalt particles by SQUID and pulsed magnetic fields up to 35 T. These measurements have been made on two samples (C1, C2) with nonagglomerated particles. The analysis of the magnetic meaurements evidences very narrow log-normal size distribution centered around 1.5nm (≅ 150 atoms) and 1.9 nm (≅ 310 atoms) for C1 and C2, respectively. Magnetization at 4.2 K seems to saturate in fields up to 5 T leading to an enhanced mean magnetic moment per atom compared to bulk value (1.72/μB). However, magnetization measurements up to 35 T do not permit to reach saturation, and show a continuous increase of μCo reaching 2.1 ± 0.1μB (C1) and 1.9 ± 0.1μB (C2). The effective magnetic anisotropies are found to be larger than those of bulk materials and decrease with increasing particle size. These features are associated with the large influence of the surface atoms.
AB - We measure the magnetization of fine cobalt particles by SQUID and pulsed magnetic fields up to 35 T. These measurements have been made on two samples (C1, C2) with nonagglomerated particles. The analysis of the magnetic meaurements evidences very narrow log-normal size distribution centered around 1.5nm (≅ 150 atoms) and 1.9 nm (≅ 310 atoms) for C1 and C2, respectively. Magnetization at 4.2 K seems to saturate in fields up to 5 T leading to an enhanced mean magnetic moment per atom compared to bulk value (1.72/μB). However, magnetization measurements up to 35 T do not permit to reach saturation, and show a continuous increase of μCo reaching 2.1 ± 0.1μB (C1) and 1.9 ± 0.1μB (C2). The effective magnetic anisotropies are found to be larger than those of bulk materials and decrease with increasing particle size. These features are associated with the large influence of the surface atoms.
KW - Cobalt
KW - Effective magnetic anisotropy
KW - Fine particle
KW - Magnetization
UR - http://www.scopus.com/inward/record.url?scp=0032066125&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032066125&partnerID=8YFLogxK
M3 - Article
VL - 246-247
SP - 532
EP - 536
JO - Physica B: Condensed Matter
JF - Physica B: Condensed Matter
SN - 0921-4526
ER -