skip to main content

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

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 coercivemore » field—remained unchanged.« less
Authors:
 [1] ;  [2] ;  [3] ; ;  [1] ;  [4] ;  [5]
  1. Kirensky Institute of Physics SB RAS, Krasnoyarsk (Russian Federation)
  2. (Russian Federation)
  3. Krasnoyarsk Institute of Railways Transport, Krasnoyarsk (Russian Federation)
  4. Institut fur Sicherheitsforschung und Reaktortechnik, D-52425 Juelich (Germany)
  5. Krasnoyarsk Scientific Center SB RAS, Krasnoyarsk (Russian Federation)
Publication Date:
OSTI Identifier:
22273730
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal 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)
Country of Publication:
United States
Language:
English
Subject:
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