Authors: N Ammouchi A Otmani Z Bensebaa S Azzaza M Bououdina A Djekoun L Bechiri J M Grénèche
Publish Date: 2015/09/07
Volume: 28, Issue: 12, Pages: 3651-3661
Abstract
Nanostructured Fe65Si20Cr15 powders were prepared by mechanical alloying in a planetary ball mill Morphological microstructural structural and magnetic characterizations of the milled powders were investigated by scanning electron microscopy Xray diffraction Mössbauer spectroscopy and vibrating sample magnetometer A mixture of substitutional bcc FeSi ˜29 nm and bcc CrSi ˜45 nm is obtained after 3 h of milling Upon prolonged milling all the asmilled powders exhibit nonequilibrium αFeSiCr solid solution with an average crystallite size of 19–23 nm The lattice parameter decreases initially up to 3 h and then increases with further increase in milling time due to dissolution of Cr and Si into Fe host lattice The variation of microstructural parameters such as average crystallite size rms microstrain static Debye–Waller parameter and dislocation density as a function of milling time show good correlations Mössbauer spectra of the milled powders recorded at room temperature reveal the decrease of the average hyperfine field suggesting a random distribution of atoms during milling and point out the formation of the disordered bcc FeSiCr solid solution After 15 h of milling the coercivity and magnetization values are 817 Oe and 1203 emu/g respectively
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