Effect of ball milling and dynamic compaction on magnetic properties of Al{sub 2}O{sub 3}/Co(P) composite particles

Journal Article · Wed May 07 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4869158· OSTI ID:22273730

Denisova, E. A. ^[1]; Kuzovnikova, L. A. ^[2]; Eremin, E. V. ^[1]; Bukaemskiy, A. A. ^[3]; Nemtsev, I. V. ^[4]

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1. Kirensky Institute of Physics SB RAS, Krasnoyarsk (Russian Federation)
2. Krasnoyarsk Institute of Railways Transport, Krasnoyarsk (Russian Federation)
3. Institut fur Sicherheitsforschung und Reaktortechnik, D-52425 Juelich (Germany)
4. Krasnoyarsk Scientific Center SB RAS, Krasnoyarsk (Russian Federation)

The evolution of the magnetic properties of composite Al{sub 2}O{sub 3}/Co(P) particles during ball milling and dynamic compaction is investigated. To prepare starting composite particles, the Al{sub 2}O{sub 3} granules were coated with a Co{sub 95}P{sub 5} shell by electroless plating. The magnetic and structural properties of the composite particles are characterized by scanning electron microscopy, X-ray diffraction, and the use of the Physical Property Measurement System. The use of composite core-shell particles as starting powder for mechanoactivation allows to decrease treatment duration to 1 h and to produce a more homogeneous bulk sample than in the case of the mixture of Co and Al{sub 2}O{sub 3} powders. The magnetic properties of the milled composite particles are correlated with changes in the microstructure. Reduction in grain size of Co during milling leads to an increase of the volume fraction of superparamagnetic particles and to a decrease of the saturation magnetization. The local magnetic anisotropy field depends on the amount of hcp-Co phase in sample. The anisotropy field value decreases from 8.4 kOe to 3.8 kOe with an increase in milling duration up to 75 min. The regimes of dynamic compaction were selected so that the magnetic characteristics—saturation magnetization and coercive field—remained unchanged.

• OSTI ID: 22273730
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 17; Conference: 55. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 14-18 Nov 2010; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
ALUMINIUM OXIDES
ANISOTROPY
COBALT
COMPOSITE MATERIALS
GRAIN SIZE
HCP LATTICES
INTERFACES
MAGNETIC PROPERTIES
MAGNETIZATION
MILLING
MIXTURES
PARTICLES
POWDERS
SCANNING ELECTRON MICROSCOPY
SUPERPARAMAGNETISM
X-RAY DIFFRACTION