Abstract
Magnetic properties of small particles of iron oxide on an aluminum foil and a single crystal of MgO are studied by conversion electron Mössbauer spectroscopy (CEMS) at low temperature. The average thickness of the oxide layers is 3.0 nm on aluminum and 1.2 nm on MgO. The CEMS spectra are observed at 15-300 K with a gas-filled proportional counter which was developed in our laboratory. The hyperfine fields in the surface layer and in the core of the particles are separated. The diameter and magnetic anisotropy energy constant are 3.7 nm and 0.87 × 105 J/m3, and 3.5 nm and 2.4 × 105 J/m3, respectively, for small particles on aluminum and MgO. The large difference in the anisotropy constants of small particles on aluminum and MgO is attributed to the enhanced surface anisotropy, which may be caused by diffusion of magnesium ions into the lattice of iron oxide. The superparamagnetic blocking temperatures of these particles are 71 and 94 K, respectively.
| Original language | English |
|---|---|
| Pages (from-to) | 175-180 |
| Number of pages | 6 |
| Journal | Journal of Magnetism and Magnetic Materials |
| Volume | 145 |
| Issue number | 1-2 |
| DOIs | |
| Publication status | Published - Mar 1 1995 |
Fingerprint
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
Cite this
Magnetic properties of iron-oxide small particles prepared on aluminum and MgO(100). / Fukumura, K.; Nakanishi, A.; Fujii, Tatsuo; Kobayashi, T.
In: Journal of Magnetism and Magnetic Materials, Vol. 145, No. 1-2, 01.03.1995, p. 175-180.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Magnetic properties of iron-oxide small particles prepared on aluminum and MgO(100)
AU - Fukumura, K.
AU - Nakanishi, A.
AU - Fujii, Tatsuo
AU - Kobayashi, T.
PY - 1995/3/1
Y1 - 1995/3/1
N2 - Magnetic properties of small particles of iron oxide on an aluminum foil and a single crystal of MgO are studied by conversion electron Mössbauer spectroscopy (CEMS) at low temperature. The average thickness of the oxide layers is 3.0 nm on aluminum and 1.2 nm on MgO. The CEMS spectra are observed at 15-300 K with a gas-filled proportional counter which was developed in our laboratory. The hyperfine fields in the surface layer and in the core of the particles are separated. The diameter and magnetic anisotropy energy constant are 3.7 nm and 0.87 × 105 J/m3, and 3.5 nm and 2.4 × 105 J/m3, respectively, for small particles on aluminum and MgO. The large difference in the anisotropy constants of small particles on aluminum and MgO is attributed to the enhanced surface anisotropy, which may be caused by diffusion of magnesium ions into the lattice of iron oxide. The superparamagnetic blocking temperatures of these particles are 71 and 94 K, respectively.
AB - Magnetic properties of small particles of iron oxide on an aluminum foil and a single crystal of MgO are studied by conversion electron Mössbauer spectroscopy (CEMS) at low temperature. The average thickness of the oxide layers is 3.0 nm on aluminum and 1.2 nm on MgO. The CEMS spectra are observed at 15-300 K with a gas-filled proportional counter which was developed in our laboratory. The hyperfine fields in the surface layer and in the core of the particles are separated. The diameter and magnetic anisotropy energy constant are 3.7 nm and 0.87 × 105 J/m3, and 3.5 nm and 2.4 × 105 J/m3, respectively, for small particles on aluminum and MgO. The large difference in the anisotropy constants of small particles on aluminum and MgO is attributed to the enhanced surface anisotropy, which may be caused by diffusion of magnesium ions into the lattice of iron oxide. The superparamagnetic blocking temperatures of these particles are 71 and 94 K, respectively.
UR - http://www.scopus.com/inward/record.url?scp=0029271474&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029271474&partnerID=8YFLogxK
U2 - 10.1016/0304-8853(94)00864-7
DO - 10.1016/0304-8853(94)00864-7
M3 - Article
AN - SCOPUS:0029271474
VL - 145
SP - 175
EP - 180
JO - Journal of Magnetism and Magnetic Materials
JF - Journal of Magnetism and Magnetic Materials
SN - 0304-8853
IS - 1-2
ER -