Structural and magnetic properties of the nanocomposite materials based on a mesoporous silicon dioxide matrix

Journal Article · Wed Mar 15 00:00:00 EDT 2017 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S106377611702011X· OSTI ID:22617048

Eckerlebe, H. ^[1]; Eliseev, A. A.; Lukashin, A. V.; Napol’skii, K. S. ^[2]; Kraje, M. ^[3]; Grigor’ev, S. V. ^[4]

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1. Helmholtz-Zentrum Geesthacht (Germany)
2. Moscow State University (Russian Federation)
3. Reactor Institute Delft (Netherlands)
4. St. Petersburg State University (Russian Federation)

The structural and magnetic properties of the mesoporous systems based on silicon dioxide with a regular hexagonal arrangement of pores several microns in length and several nanometers in diameter, which are filled with iron compound nanofilaments in various chemical states, are studied in detail. The studies are performed using the following mutually complementary methods: transmission electron microscopy, SQUID magnetometry, electron spin resonance, Mössbauer spectroscopy, polarized neutron small-angle diffraction, and synchrotron radiation diffraction. It is shown that the iron nanoparticles in pores are mainly in the γ phase of Fe{sub 2}O{sub 3} with a small addition of the α phase and atomic iron clusters. The effective magnetic field acting on a nanofilament from other nanofilaments is 11 mT and has a dipole nature, the ferromagnetic–paramagnetic transition temperature is in the range 76–94 K depending on the annealing temperature of the samples, and the temperature that corresponds to the change in the magnetic state of the iron oxide nanofilaments is T ≈ 50–60 K at H = 0 and T ≈ 80 K at H = 300 mT. It is also shown that the magnetization reversal of an array of nanofilaments is caused by the magnetostatic interaction between nanofilaments at the fields that are lower than the saturation field.

• OSTI ID: 22617048
• Journal Information: Journal of Experimental and Theoretical Physics, Vol. 124, Issue 3; Other Information: Copyright (c) 2017 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
ANNEALING
DIFFRACTION
DIPOLES
ELECTRON SPIN RESONANCE
FILAMENTS
IRON OXIDES
MAGNETIC FIELDS
MAGNETIC PROPERTIES
MAGNETIZATION
MOESSBAUER EFFECT
NANOCOMPOSITES
NANOPARTICLES
NANOSTRUCTURES
PARAMAGNETISM
SILICON OXIDES
SPIN
SQUID DEVICES
SYNCHROTRON RADIATION
TRANSITION TEMPERATURE
TRANSMISSION ELECTRON MICROSCOPY