Magnetic and structural properties of nanostructured Fe–20Al–2Cr powder mixtures

Journal Article · Sun Feb 15 00:00:00 EST 2015 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2014.12.010· OSTI ID:22476028

Zerniz, N. ^[1]; Chater, R. ^[1]; Abbas, H. ^[2]; Bououdina, M. ^[3]; Bouchelaghem, W. ^[1]

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1. Laboratory of Inorganic Materials Chemistry, Chemistry Department, University Badji Mokhtar of Annaba, BP: 12, Annaba 23000 (Algeria)
2. Department of Biology, College of Science, University of Bahrain, PO Box 32038 (Bahrain)
3. Nanotechnology Centre, University of Bahrain, PO Box 32038 (Bahrain)

Nanostructured Fe–20Al–2Cr (wt.%) powders have been prepared using high energy planetary ball-mill. Changes in structural, morphological and magnetic properties of the powders during mechanical alloying (MA) and during subsequent annealing have been examined by X-ray diffraction, scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The observed structural and microstructural changes have been related to several processes occurring during MA. After MA, the material becomes significantly disordered and refines to nanoscale grain sizes (~ 14 nm). The obtained bcc α-Fe(Al,Cr) solid solution shows a ferromagnetic behavior. Upon subsequent annealing at 400 °C, α-Fe{sub 2}O{sub 3} and spinel oxides are formed at the surface of particles, while structural defects disappeared as Fe(Al,Cr) solid solution becomes more ordered and grain growth occurs. The saturation magnetization (Ms) shows lower values after annealing, attributed to the formation of metal oxides with low magnetic moment. - Graphical abstract: Display Omitted - Highlights: • Nanostructured Fe–Al–Cr powders were prepared by MA. • Careful analysis of the XRD patterns by using the Rietveld refinement • The lattice distortion is evidenced by the increase of both the lattice parameter and the static Debye Waller parameter. • Annealing at 400 °C stabilizes the microstructure at the nanometer range and leads to the formation of Fe{sub 3}O{sub 4} and Fe{sub 2}O{sub 3} oxides. • Both the milled and annealed samples are ferromagnetic.

• OSTI ID: 22476028
• Journal Information: Materials Characterization, Vol. 100; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-5803
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM COMPOUNDS
BCC LATTICES
CHROMIUM COMPOUNDS
DEBYE-WALLER FACTOR
DEFECTS
FERRITES
IRON COMPOUNDS
IRON OXIDES
LATTICE PARAMETERS
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MAGNETIZATION
NANOMATERIALS
NANOSTRUCTURES
SCANNING ELECTRON MICROSCOPY
SOLID SOLUTIONS
SURFACES
TERNARY ALLOY SYSTEMS
VIBRATING SAMPLE MAGNETOMETERS
X-RAY DIFFRACTION